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92 D555* 57-06931 

Wilson ^ T7CQ 

Diderot The testing years, 1715-1759 

9 2 


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Bust of Diderot, by Ilouclon (1771; 






Library of Congress Catalogue Card Number: 57-8485 



C.Z.W. and A.M.W., Sr, 

And to 

M.Z.G. and R.W.G., 

In Gratitude and Appreciation 


A RECENT REVIEWER in The Times Literary Supple 
ment remarked, regarding Diderot, that among 

the great minds of the eighteenth century Diderot has received less atten 
tion in this country than he deserves. 

Yet interest in Diderot has been increasing markedly of late. Partly 
this is because of an ever-widening persuasion that he has been too much 
neglected and too little understood. Partly it is because of the publicity at 
tendant upon the celebration in 1951 of the bicentenary of the Encycloptdie. 
Most of all, it is because of the growing conviction of biographers, historians, 
and critics that Diderot was not only one of the most representative men of 
his age but also one of the most glowingly modern figures of the eighteenth 
century. Certainly for Americans, who are children of the Enlightenment 
to a degree that is unique among twentieth-century peoples, the life and 
times of Diderot can have unusual interest and relevancy. 

This book has therefore been written in the hope of meeting the needs 
of two audiences the general reader and the specialist. The general reader, 
if he has no previous knowledge about Diderot, has a right to be shown 
why Diderot and Diderot s times and Diderot s vicissitudes should interest 
him. As for the specialist, it is hoped that the bibliographical information con 
tained in this book will be useful; and that even for him a conspectus of 
the early career of Diderot will be of interest. 

The reader will discover in the following chapters a good deal more 
information regarding the contents of the Encyclopedic than is usual in 
biographies of Diderot. By this analysis and description of the contents of 
such a great work of reference and instruction, it is hoped that the reader 
will gain a more vivid insight into the intellectual conditions of the Age 
of Enlightenment. 

For every researcher it is a pleasure to record his obligations to the various 



libraries that have aided him in his work. In this instance, the author is 
under the greatest debt to the Dartmouth College Library and to the Bibli- 
otheque Nationale. Also of very great assistance were the Library of Con 
gress, the Mazarine and the Bibliotheque de 1 Arsenal at Paris, the British 
Museum, the Bodleian Library, the New York Public Library, the Boston 
Public Library, and the university libraries of Harvard, Princeton, Yale, 
Iowa, Pennsylvania, Michigan, and Wisconsin. I also hold in grateful recollec 
tion all the numerous libraries, from Quebec to San Marino I fear to list 
them lest the enumeration grow tedious where, during vacation or sab 
batical leave, we have sought out the manuscript source or the rare edition 
or the comparatively inaccessible book. To the administrations and staffs of 
all these institutions I here record my heartfelt thanks. 

Research on Diderot has of course entailed the pleasant necessity of wander 
ing about in Paris and Langres, seeking the sites and buildings associated 
with events in his life. In this connection I particularly desire to record my 
thanks to the Mayor and Deputy Mayor of Langres, M. Beligne and M. FAbbe 
Rabin, for their courtesy and hospitality, as well as to express my apprecia 
tion of these qualities in the Librarian of the Municipal Library of Langres, 
the late M. Populus. 

During the time when this book was in preparation, Dartmouth College 
granted me two years of sabbatical leave, as well as a reduction of teaching 
duties during one semester. I gratefully acknowledge this assistance, as also 
the fellowship granted by the John Simon Guggenheim Memorial Founda 

Grateful acknowledgment is also made to the Editions de Minuit, Paris, 
for permission to quote from M. Georges Roth s edition of Diderot s Corre- 
sp on dance; and to the Librairie Armand Colin, Paris, for permission to quote 
from the Dufour-Plan edition of Rousseau s Correspondence g&n&rale. 

Several persons have had the kindness to read this book in manuscript. 
It has materially benefited from the judgment of Professor Thomas G. Bergin 
of Yale University, Professor W. M. Frohock of Harvard University, Pro 
fessor Hayward Keniston of Duke University, Professor H. W. Victor Lange 
of Cornell University, and Professor Norman L. Torrey of Columbia Uni 
versity. To all of these scholars I desire to acknowledge gratefully my in 
debtedness. I have also been the beneficiary of the counsel of Professors 
Charles R. Bagley and Frangois Denoeu, both of Dartmouth College, and 
Mr. Bradford Martin, of Thetford Hill, Vermont. Each has offered valuable 
suggestions from which I have greatly profited. 

Two persons in particular have been of indispensable assistance in bring- 


ing this book into being. The first is Professor Ira O. Wade of Princeton 
University, whose helpful and encouraging suggestions are most gratefully 
acknowledged. The other is my wife. My debt to her, as research assistant 
and critic, simply defies description. So does my appreciation. 


Hanover, New Hampshire 
March 1957 


Prologue, 3 

1. Diderot s Family and Early Childhood, 9 

2. Diderot Becomes an Abbe and Goes to Paris, 20 

3. Clandestine Marriage, 37 

4. First Fruits, 47 

5. The Emerging Philosophe, 59 

6. The Early History of the Encyclopedic, 73 

7. Two Very Different Books, 83 

8. Letter on the Blind, 92 

9. Diderot in Prison, 103 

10. The Prospectus of the Encyclopedic, and Letter on the Deaf and Dumb, 


11. What Readers Found in Volume I of the Encyclopedic, 130 

12. Up till Now, Hell Has Vomited Its Venom Drop by Drop/ 150 

13. The Encyclopedic Recontinued, 161 



14. Italian Opera and French Taste, 173 

15. Diderot s Thoughts on the Interpretation of Nature, 187 

16. Man Is Born To Think for Himself, 199 

17. Business and Pleasure: A New Contract, Mme Geofirin s Salon, 

Sophie Volland, 218 

1 8. Changing the General Way of Thinking, 232 

19. Growing Tension with Rousseau: Only the Bad Man Lives Alone, 247 

20. How To Write a Play: Example and Precept, 260 

21. Rising Opposition; DAlembert s Blunder in Volume VII, 275 

22. I Used To Have an Aristarchus ... I Wish To Have Him No Longer/ 


23. Signs and Portents of Approaching Eclipse, 307 

24. Le Pere de Famille and the Discourse on Dramatic Poetry/ 322 

25. The Death of the Phoenix, 332 
Epilogue, 343 

List of Abbreviations, 347 
Notes, 349 
Bibliography, 399 
Index, 405 




The Announcement of an Important Event 


[N NOVEMBER of 1750 there took place in Paris what 
might seem to be nothing more than an inconsider 
able occurrence in the realm of letters. An editor of a forthcoming encyclo 
pedia published a prospectus explaining to a hoped-for public what would 
be the content of his work and the principles of his editorial policy. Yet the 
work thus announced secured so many readers, the ideas it contained modi 
fied current thinking to such a degree, that now the publication of its 
prospectus is recognized as one of the most important events in the political 
as well as the intellectual history of the eighteenth century. To symbolize 
this importance, the French government published in 1950 a reprint in 
national commemoration of the bicentenary of the event. 

The prospectus sought favor in a world familiar to us through the paint 
ings of Nattier, Boucher, and Lancret a world in which the charming 
gracefulness and frivolity of the rococo was succeeding to the stately majesty 
of the baroque. It was the world of wigs, smallclothes, and three-cornered 
hats; of panniers and beauty patches and pancakes of rouge laid on delicate 
cheeks. It was the world of the minuet, danced in rooms gleaming with gilt 
and shimmering with mirrors; of Meissen figurines and of ladies as fragile 
as the porcelain that portrayed them; the world of the harpsichord, the 
recorder, and the viola da gamba; of the musket, the frigate, and the balance 
of power. This was the time when Russia was becoming more important 
in European diplomacy, when Frederick II of Prussia was astonishing 
Europe by his temerity and dumbfounding it by his success. It was the time 
when immense French and British colonial empires were in the making and 
were providing stakes for great colonial wars. In the American context, it 
was the time that lay between King George s War and the French and 
Indian War, between the proud conquest of Louisbourg by the men of 
Massachusetts and the defeat of Braddock in the western forests. It was a 


time when the Church patently expected to continue confining men s 
thoughts within a narrow orthodoxy, and privileged classes patently expected 
to continue enjoying their privileges. Yet it was also a time when the mer 
chant, banking, and professional elements of society were everywhere rising 
in esteem and wealth. In 1750 Johann Sebastian Bach had just breathed his 
last, Henry Fielding had published Tom Jones, Dr. Samuel Johnson was 
laboring upon his famous Dictionary, and George Washington was eighteen 

years old. 

The prospectus was published in a country which was far from being be 
nighted. Yet it was one which, in its acceptance of inequalities and in its 
denial of civil liberties, fell some distance short of Utopia. It was a society 
in which prisons and galleys existed for those confessing the Protestant faith, 
where one of the duties o the public executioner was the burning of books, 
where valor in the service of one s country could never quite make up for the 
lack of noble birth, where a peasantry dressed in rags, where a villager might 
find his taxes enormously and arbitrarily increased if the tax collector espied 
any chicken feathers on the doorstep, where decent burial could be refused 
to those who did not make their peace with the Church, where nothing could 
be legally published without undergoing censorship, and where a man could 
lawfully be arrested and indefinitely detained without cause being shown. 

The prospectus announced a work so new in idea that even its name was 
unfamiliar and had to be explained, with learned reference to the Greek 
roots: The word "Encyclopedia" signifies the interrelationship of the sciences. 
And in order to give a visual presentation of the interrelationships of the 
branches of learning, the author appended to his prospectus a much-admired 
chart of human knowledge. The visualized relationships in this genealogical 
tree of all the sciences and all the arts/ avowedly modeled upon a similar 
project by Lord Bacon, were to be emphasized constantly in the body of the 
work by means of cross reference. 

Clearly the author of the prospectus coveted for people, as do present-day 
proponents of general education, the pleasure and excitement that comes 
from realization of how knowledge is interrelated and interlocked. This 
effort at integration was to be one of the proposed work s greatest entice 
ments. It was to be accomplished, wrote the author, by Indicating the connec 
tions, both remote and near, of the beings that compose Nature and which 
have occupied the attention of mankind; of showing, by the interlacing of 
the roots and branches, the impossibility of knowing well any parts of this 
whole without ascending or descending to many others; of forming a general 
picture of the efforts of the human mind in all fields and every century; of 


presenting these objects with clarity; of giving to each one of them its appro 
priate length, and, if possible, of substantiating by our success our epigraph 
[a quotation from Horace]: 

So great is the power of order and arrangement; 

So much grace may be imparted to a common theme/ 

The French public had never before been offered just such an opportunity. 
England had had a successful Cyclopaedia, edited by Ephraim Chambers 
and published in two volumes in 1728. Indeed, it was this Cyclopaedia that 
provided the stimulus for the great work of reference now to be published 
in France. But the French work promised to outstrip its predecessor in size 
and coverage. Moreover, it would possess the advantage of being published 
in a language that, unlike the comparatively little-known English of that day, 
was the circulating medium of ideas, the common coin, of all educated men. 

The work thus announced was to be the result of the combined labor of a 
considerable number of well-known men of letters, experts, and specialists. 
It was to consist of ten volumes in folio, of which two were to contain en 
gravings. This size would allow a range of subject matter vastly greater than 
that of any existing work of reference. It was thus hoped to provide a book 
which one might consult on every subject/ The aim of the French En 
cyclopedia, as set forth in its prospectus/ wrote Frank Moore Colby, the 
American encyclopedist and essayist, was to serve as a reference library for 
every intelligent man on all subjects save his own. That has remained the 
aim of general encyclopedias ever since/ 

The lack of a comprehensive and extensive encyclopedia is hard for us, 
who have such an abundance of excellent ones, to understand. But the author 
of the prospectus was announcing his work at a time when the first edition 
of the Encyclopaedia Britannic a was twenty-one years in the future, and he 
could say quite rightly that no existing work of reference did justice to the 
great names and the great intellectual accomplishments of the seventeenth 
century. What progress has not since been made in the sciences and the 
arts? asked the author of the prospectus, speaking of his puny and outworn 
predecessors. How many truths known today, but only glimpsed then? 
True philosophy was in its cradle [the author of the prospectus did not care 
for scholastic philosophy] ; the geometry of the infinite was not yet in being; 
experimental physics was just beginning to show itself; the laws of sound 
criticism were entirely ignored. Descartes, Boyle, Huyghens, Newton, 
Leibniz, the Bernoullis, Locke, Bayle, Pascal, Corneille, Racine, Bourdaloue, 
Bossuet, etc., either did not exist or had not written/ 


The Encyclopedic was, in fact, very fortunate in its time of publication, 
for it fitted exactly into the intellectual and social needs of the time. We know 
now that the eighteenth century was moving more rapidly toward radical 
change, was more in need of it, than the age itself realized. It was not merely 
that new conceptions of truth, stemming from current hypotheses about 
physics and psychology, were having a profoundly unsettling effect upon 
conventional ideas of morality, religion, and even politics; it was also that 
the middle classes were daily becoming more qualified to exercise power 
while being denied their share of it; that a new technology was beginning, 
whether as cause or effect of the incipient Industrial Revolution; that new 
theories as to what constitutes the wealth of nations were in gestation; that 
new doctrines of agricultural husbandry were beginning to be canvassed; 
and that changing economic conditions were beginning to call attention to 
such matters as the legal status of peasants and town workers, the supply of 
labor, the incidence of taxation, and the conditions of occupancy of land. 

No doubt the significance of these changes or of these emerging prob 
lems was hidden save in glimpses to a few whom Carlyle would term 
Seers, and of whom the author of the prospectus was one. But even though 
the ordinary citizen of the eighteenth century might not recognize the 
massiveness of the changes that were overtaking his world, he would 
probably have been aware, however obscurely, that a certain this-worldliness 
was beginning to overlie the emphasis of preceding generations on othcr- 
worldliness. Somehow he now seemed to need to know, or want to know, 
the names of more objects, the application of more theories, the purpose 
of more tools, and the geographical location of more places than ever before. 
The places and objects and relationships of a secular existence were in 
creasingly obtruding themselves upon the attention of the most nonchalant, 
the most frivolous, the most devout. 

The Encyclopedic was precisely the means for giving information about 
these myriads of external objects and relationships, especially as its principal 
editor, the author of its prospectus, was himself the son of a craftsman and 
had an extremely lively interest in the technology and craftsmanship of the 
day. Certainly no one preached the dignity of labor more adroitly than he, 
and to this purpose he went to great lengths to make his Encyclopedic a 
repository of knowledge concerning the mechanical arts: 

. . . Everything accordingly impelled us to have recourse to the workers them 
selves. We went to the cleverest ones in Paris and in the kingdom. We took the 
pains of going into their workshops, of questioning them, of writing under their 
dictation, of developing their thoughts, of educing from them the terms peculiar 


to their profession, of drawing up tables of such terms, of defining them, of con 
versing with those persons from whom we had obtained memoranda and (an 
almost indispensable precaution) of rectifying, in long and frequent conversations 
with some, what others had imperfectly, obscurely, or unfaithfully explained. 

Some crafts were so complicated, the prospectus remarked, that it was 
necessary to learn to operate the machines and even to construct them before 
the craft could be accurately described. And the author explained that drafts 
men had been sent into the workshops to prepare drawings from which 
engravings for the Encyclopedic would be made. 

The promises made by the prospectus were widely welcomed. The Mercure 
de France, remarking that the prospectus was much appreciated by the pub 
lic, printed lengthy quotations from it. The magisterial and somewhat 
ponderous Journal dcs Sgavans spoke of the project as one of the most 
interesting and costly since the invention of printing . . . and spoke with 
no less approbation of the drawings, *of which we have seen a very consider 
able part, [and which] are of great beauty. And the youthful Adam Smith, 
writing for the Edinburgh Review in 1755, declared that: The French work 
which I just now mentioned, promises to be the most compleat of the kind 
which has ever been published or attempted in any language. 

The need for the promised work was proved in the most convincing way 
of all: subscribers names on the dotted line, subscribers money in down 
payments. By the end of April 1751, a little less than six months after the 
prospectus had been published, there were 1,002 subscribers, each of them 
paying a deposit of 60 livres for a work scheduled to cost 280 livres in all. 
By the end of the year the number of subscribers had risen to 2,619, and the 
number finally rose to about 4000, to say nothing of the subscribers to several 
editions pirated in Italy and Switzerland. The demand, moreover, was 
general throughout the Western world. The publishers later asserted that 
nearly three-fourths of the 4000 subscriptions were taken up in the provinces 
or by foreigners. 

The subscribers got the information they paid for but conjoined with a 
special point of view. So distinctive was the particular outlook of the En 
cyclopedic (and of its editor, the author of the prospectus) that it infuriated 
many persons, while preparing many others for the reforms brought about 
by the Revolution of 1789. The contents of the Encyclopedic will be described 
in more detail later. Here it suffices to say that the Encyclopedic trusted 
much to the operation of common sense, and was not afraid of change. 
Essentially, what it advocated can be quite accurately described to American 
readers as Hamiltonianism plus the Bill of Rights. And because it gave 


currency to these ideas, it has often been called the Trojan Horse of the 
ancien regime. 

There were many people and many vested interests in eighteenth-century 
France who did not want Hamiltonianism and the Bill of Rights. Their 
perfervid opposition made the expression of such ideas hazardous, espe 
cially since the Encyclopedic depended for publication upon an official 
license, a license which was twice taken away and only very grudgingly and 
qualifiedly restored. Therefore, to have the tact and energy and courage 
sufficient to keep the enterprise going, and to combine these with the in 
tellectual breadth requisite in an editor of so vast a work, called for unusual 
qualities in unusual conjunction. These the author of the prospectus has 
always been acknowledged to have. At the distance of some centuries/ wrote 
Jean-Jacques Rousseau, . . . [he] will seem a prodigious man. People will 
look from afar at that universal head with commingled admiration and 
astonishment as we look today at the heads of Plato and Aristotle. 
It is this prodigious man who is the subject of this book. 
Yet with all his prodigiousness, he still had much to learn and much to 
endure when he wrote his prospectus. Dedicated to the task he had ac 
cepted, he fortunately could not foresee the rigors of the years ahead, the 
enemies he was destined to arouse, the anxieties and frustrations he would 
have to experience before the mammoth work could be brought to a suc 
cessful conclusion. In the decade between the publication of the prospectus 
and the suppression of the Encyclopedic in 1759, the Enlightenment in 
France was taking its characteristic set/ Ideas were being tested together 
with the men holding them. Of no one could this be said with greater 
aptness than of the young author of the prospectus, destined to become one 
of the great leaders of the Enlightenment in some respects the greatest of 
them all And because of this very process of testing, much of it painful, 
some of it unfelt and unseen, the author of the prospectus found himself 
equipped, ten years after it was written, to cope successfully with the greatest 
and longest crisis of his life. 
This book is the story of that preparation. 


Diderot s Family and Early Childhood 


"ANGRES, the pleasant but somewhat austere old 
f Roman town in which Denis Diderot was born, 
is situated imposingly and rather self-consciously on the northern extremity 
of the plateau of Langres, so that the land falls sharply away from it on 
three sides, and one of the principal modes of communication with the 
outside world is a cog railway connecting it with the nearby Paris-Basel 
railway line. The city is well remembered by many members of the AEF 
of 1917-18 as the site of numerous staff and training schools. No doubt many 
veterans (of both wars) will recall, as in their mind s eye they make the 
deliberate but exhilarating ascent, the bulk of the massive Charity Hospital, 
the old towers on the city walls, the second-century Gallo-Roman gate, and 
the delightful walk on the ramparts around the town, from which one over 
looks the nearby plain where the River Marne has its source and can extend 
one s gaze in the direction of the Vosges and the Alps. 

Perhaps they will remember, too, the rather severe-looking old houses, 
which frequently conceal a Louis XIV interior or screen a Renaissance 
garden front; the grimy children playing in the streets (Langres, because 
of its location, is short of playgrounds and water) ; the rather unusual num 
ber of priests and nuns, for Langres is still a conspicuously pious town; and 
a general air of quietude of which the inhabitants are very proud, speaking 
as they do of the calm of our provincial cities, in transparent allusion to 
the bustle of iniquitous Paris. 

It is easy for the visitor to Langres to feel a wistfulness for the long ago 
and far away. Even Diderot himself, never inclined to be unduly senti 
mental about the native town from which he had emancipated himself 
although he was often a touch sentimental about other things experienced 
on a visit to Langres in his middle age something of the spell exerted by 
tranquil and beautiful surroundings in a place where life has been flowing 



in the same channels for many generations. We have here/ he wrote to 
Sophie Volland, a charming promenade, consisting of a broad aisle of 

thickly verdured trees leading to a small grove tis there that I come 

afternoons at five. My eyes wander over the most beautiful landscape m the 

wor ld I pass hours in this spot, reading, meditating, contemplating 

nature, and thinking of my love/ 1 The Park of the White Fountain, to the 
south and through the Gate of the Windmills, is now, as it was when Diderot 
described it in 1759, a place of beauty and of hushed delight. 

Diderot later commemorated the history and antiquities of Langres in an 
article inserted in the Encyclopedic. This exercise in civic piety, couched in 
sentences uncharacteristically dry and antiquarian, recalled that Langres had 
been the ancient Andematunum, the capital city of the Lingones; that it 
was situated in Champagne, fourteen leagues from Dijon, forty from Reims, 
and sixty-three from Paris; and that it was the seat of a bishop. 2 Diderot 
might also have remarked that it lies in good wine country, that it had 
when he wrote a population of about ten thousand, and that it had long 
been celebrated for the quality of the cutlery that its craftsmen produced. 

One of the characteristics for which Diderot became famous was a zest 
not to say a weakness for the divagatious. This intellectual volatility he 
ascribed, half-whimsically, half-seriously, to the climate of Langres. The 
inhabitants of this district have great wit, too much vivacity, and the in 
constancy of weather-vanes, he wrote. This comes, I believe, from the 
changes in their atmosphere, which passes in twenty-four hours from cold 
to hot, from calm to stormy, from clear to rainy. . . . Thus they accustom 
themselves from the most tender infancy to turn to every wind. The head 
of a man from Langres is set upon his shoulders the way a cock is set upon 
the top of a belfry. . . . Yet with such a surprising rapidity in their move 
ments, desires, projects, fantasies, and ideas, they have a drawling speech 
.... As for me, I am of my district, except that residence in the capital and 
assiduous application have somewhat corrected me. 3 

The appearance of the town reflected then, as it does today, the piety of a 
community traditionally devoted to Roman Catholicism. There were (and 
still are) standing in little niches in the housefronts charming madonnas 
carved in the hard and unweathering stone of the neighborhood. There 
was (and still is) the cathedral, dedicated to Saint-Mammes, a more than 
shadowy Cappadocian whose martyred head is said to have been brought 
to Langres soon after his death, which occurred about 274. There were the 
churches of Saint-Martin and Saint-Pierre, in the latter of which Diderot was 
baptized. 4 There was the church of Saint-Didier (now one of the local 


museums), dedicated to a sainted but somewhat misty bishop of Langres 
who was martyred about 264 and whose tomb may be seen in the apse of the 
museum. It is believed to have been the image of this local saint, cradling 
his mitred and martyred head in his arm, that occupied the Louis XIII 
niche in the facade of the house in which Diderot grew up. 5 Finally, there 
was the great crucifix standing in the Place Chambeau, the Place upon which 
the Diderot home faced. The square is still there, now appropriately named 
the Place Diderot. The crucifix is not. A statue of Diderot, done in 1884 by 
Frederic-Auguste Bartholdi, the sculptor of the Statue of Liberty, has re 
placed it. There is little doubt that Diderot would have been vastly amused 
if he could have foreseen such a triumphant usurpation. 

For Diderot came to be an earnest and devoted anticlerical. It is, therefore, 
all the more piquant to observe that his closest relatives were people who 
were either extremely pious laymen or else professional religious whose lives 
were spent in the service of the Church. For example, his mother s brother, 
Didier Vigneron, was a canon at the local cathedral until his death when 
Diderot was fifteen years old. Another uncle, Jean Vigneron, was curate at 
Chassigny, ten miles south of Langres, and died there the year of Diderot s 
birth. Two uncles of Diderot s mother and two of her cousins had also been 
country priests, and on the Diderot side of the family, an uncle, Antoine by 
name, was a Dominican friar. 6 Diderot sprang from a milieu that was not 
only intimately familiar with the tradition of the Church but also not in the 
least rebellious against it. 

Such had been the way of his ancestors since the names of Diderot and 
Vigneron first began to appear in the records of the locality. The name 
Diderot crops up in Langres documents from the middle of the fifteenth 
century, that of Vigneron from 1558. Both families were of artisan stock, 
and predominantly devoted themselves through the generations to being 
either cutlers or tanners. Both families, moreover, displayed a talent for 
progenitiveness. The Encyclopedist s great-grandfather Vigneron had had 
nine children; grandfather Vigneron, eleven. Great-grandfather Diderot, 
for his part, had had fourteen children; grandfather Diderot, nine. Denis 
Diderot himself was one of a family to which seven children were born. 7 

Into this world, swarming with relatives, Diderot was born on 5 October 
1713, the year haughty old Louis XIV had to accept the Treaties of Utrecht 
which put an end to the exhausting War of the Spanish Succession. But 
the abundance of Diderot s family connections seems to have left little 
impression upon him, if one may judge from the rarity of his subsequent 
allusions to them. He never mentioned his paternal grandfather, although 



that Denis Diderot was also the boy s godfather and survived until young 
Denis was in his thirteenth yean He never referred in his letters or writings 
to his uncle, the Dominican friar, or by name to his aunt and godmother, 
Claire Vigneron, though on one occasion, it is true, he included them in 
family greetings sent through a friend. 8 And the retiring and no doubt well- 
deserving lives of the Diderot collaterals, the cousins and the cousina-german 
and the cousins twice removed, have remained, for aught of him, obscure. 

Even Diderot s mother figures only infrequently in anything he ever 
committed to paper. Angflique Vigneron, the daughter of a merchant 
tanner, was born on 12 October 1677, and married Didier Diderot, a master 
cutler, in 1711 or the beginning of 1712. It was remarkable for the period 
that she was not married before the age of thirty-four. Moreover, she was 
eight years older than her husband. Her first child, a son, was born on 
5 November 1712, and died soon thereafter. 10 Eleven months later the birth 
of a second son, the subject of this biography, partially repaired the loss, 
Diderot mentions his mother only four times, but perhaps the depth of 
feeling revealed in the last two of these passages atones for the strange^lack 
of more references. The first two allusions come in letters to his friend, 
Friedrich Melchior Grimm, in which Diderot simply remarks that he was 
absent when his mother died. 11 The third allusion is in a letter to Sophie 
Volland, written when he was forty-seven: There are two or three honest 
men and two or three honest women in this world, and Providence has 
sent them to me. ... If Providence should speak and say to me, "... I have 
given thee Didier for father and Angelique for mother; thou knowest what 
they were and what they have done for thee. What is remaining for thec 
to ask of me?," I don t know what I should say in reply. 12 

The fourth allusion to his mother dates from 1770, when Diderot was at 
Bourbonne-les-Bains and writing an account of the town and the medicinal 
properties of its waters. When one is in a country, one should inform oneself 
somewhat of what goes on there, he began. Presently, in a characteristic 
digression with characteristic dots: Now it is midnight. I am alone, and I 
bring to mind these good folk, these good parents. . . . O thou, who used 
to warm my cold feet in thy hands, O my mother! . . . 13 Diderot s deep- 
seated regard for his mother was displayed by the fact that both his daughters 
the first dying before the second was born were christened Angelique* 

Diderot was extremely fond of his father and often refers to him. Didier 
Diderot (born 14 September 1685) was so good an artisan that his surgical 
knives, scalpels, and lancets, stamped with his hallmark of a pearl, were 


much in demand. A French doctor writing in 1913 spoke with respect of 
the elder Diderot and of his lancets, which he very greatly perfected: better 
in the hand, they cut more cleanly, and the lancets with the mark o the 
pearl were sought out by all the doctors teaching medicine. I possess one 
myself, bequeathed to me by an old physician of Langres, and I understand 
without difficulty the enthusiasm of contemporaries. 14 The eminence of 
Diderot s father in his craft is attested also by the fact that in the Langres 
Museum at the Hotel du Breuil there is a pair of small scissors of a design 
perfected, tradition says, by the elder Diderot. 

Diderot s father was, moreover, a man of property who enjoyed a reputa 
tion for piety and integrity. During that same night in Bourbonne-les-Bains, 
his son wrote: *. . . one of the things that has occasioned me the greatest 
pleasure was the crabbed remark addressed to me by a local man some years 
after my father s death. I was crossing a street in my city when this man 
laid his hand on my arm and said, "Monsieur Diderot, you are a good man; 
but if you think you will ever be the equal of your father, you are mis 
taken/" 15 

How Diderot felt about his father is well illustrated by a statement that 
he made six years after the old man had died. Provoked by a dispute with a 
priest about the character of the Heavenly Father, Diderot made clear his 
sentiments concerning his earthly one: The first years I spent at Paris were 
considerably disordered; my conduct was more than sufficient to irritate my 
father, without there being any need to exaggerate it. Nevertheless, calumny 
had not been wanting. He had been told. . . . What hadn t he been told ? 
The opportunity for going to see him presented itself. I did not hesitate. I 
set out full of confidence in his goodness. I thought that he would see me, 
that I should throw myself into his arms, that both of us would shed tears, 
and that all would be forgotten. I thought right. 16 

Fifteen months after the birth of the future Encyclopedist, the eldest 
daughter, Denise, was born (27 January 1715). This sister, whom Denis 
Diderot greatly admired, sometimes referring to her, when they were both 
in middle age, as little sister and sometimes as a female Socrates, remained 
a spinster throughout her long life. Sometime in middle age she developed 
a pimple on her nose that became a cancer and entirely destroyed that part 
of her face. 17 This affliction, necessitating the use of false noses (she even 
tried one made of glass), was evidently endured in a spirit of Christian 
cheerfulness. 18 Diderot s daughter spoke of her aunt as a woman who 
possessed the rare secret of finding heaven on earth, and Diderot himself 


wrote in 1770, I love my sister to distraction, not so much because she is my 
sister as because of my taste for things excellent of their kind. How many 
fine characteristics I could mention of her if I chose! 19 

Denise was followed in the Diderot family by three other sisters about 
whom very little is known. The first, Catherine, was born sometime in 
1716 and buried 30 August 1718. The second, also named Catherine, was 
born and baptized on 18 April 1719, Then on 3 April 1720, Angelique 
Diderot was born. It was an eighteenth-century custom peculiar to Langres 
and its neighborhood, I have been told though now quite general in 
France to allow persons of extremely tender age to stand as godparents. 
Thus it was that Angelique s brother stood as godfather for this new sister 
and boldly signed the baptismal register with his own hand. 20 

It is evident, therefore, that Diderot grew up with considerable experience 
in being the elder brother of girls. When he left Langres for Paris in 1728 
or 1729, his three living sisters were, respectively, about thirteen, nine, and 
eight years old, although the second Catherine may already have died. In the 
fullness of time and, oddly, against the wishes of her family Angelique 
became a nun, an Ursuline. 21 His daughter, in her memoirs of Diderot, de 
clares that this sister became insane as a result of overwork in the convent 
and died at the age of twenty-eight. 22 This incident no doubt was one of the 
causes of Diderot s dislike of convents, which helped to provide the impetus 
many years later for his very effective novel, The Nun. 

The Benjamin of the family was a boy born on 21 March I722. 23 Didier- 
Pierre Diderot, as he was named in the baptismal ceremony in which his 
elder brother served as a proxy godfather, grew up to be a pious and evi 
dently quite thorny Catholic priest, a canon in the cathedral at Langres who 
accounted his greatest shame to be his brother s impiety. The personal rela 
tions of the two brothers, although not hateful, were none too cordial Each 
deplored the views of the other while entertaining a stubborn sort of reluc 
tant affection entirely unmixed with respect. The Canon carried his disap 
probation to the point of refusing to see his brother s daughter and her 
children, and when in 1780 he was invited by the mayor and aldermen of 
Langres to be present at a dinner where the Encyclopedist s bust, done by 
Houdon, was to be unveiled, he refused. Later, under pretext of some errand 
or other at the city hall, he went to see the bust by himself, 24 

There is no record of where or from whom Diderot received his elementary 
schooling. Indeed, there is almost no testimony extant concerning his earliest 
years, save that his daughter wrote after his death that from his tenderest 
years he gave evidence of extreme sensibility: when he was three years old 


he was taken to a public execution and came back from it so upset that he 
was attacked by a violent jaundice. 25 There are in his works occasional 
allusions to his early days, as when, criticizing the figures in a landscape by 
Hubert Robert, he remarked that a Swiss guard in the picture was stiff and 
precisely like those given me one New Year s, when I was small ; 26 or when 
he observed, perhaps in recollection of his childhood and of the ramparts of 
Langres, that it is characteristic of children to love to climb; 27 or when, writ 
ing in the Encyclopedic of the vagaries of orthography, he declared that we 
get accustomed to pronouncing one language and writing another, a bizarre 
state of affairs which has made so many tears flow in childhood. 28 Perhaps 
much of his elementary education he received in his own home, for he wrote 
late in life that arithmetic was one of the first things my parents taught 
me. 29 Regardless of how the young Diderot achieved his knowledge of the 
three R s, by the time he was ten he was qualified to begin his secondary edu 
cation and in November 1723 (most probably) was enrolled in the lowest 
form of the Jesuit college at Langres. 30 

The Jesuits exercised in Langres a monopoly of secondary education, just 
as they frequently did elsewhere in Catholic Christendom. 31 They achieved 
this pre-eminence as a result of the excellence of their teachers and their 
emphasis upon the more humane letters, the Latin and Greek which had 
stood so high in the estimation of cultivated men ever since the Humanists 
had revived the love of ancient letters. By this emphasis the Jesuits, who 
were the prime instruments of the Catholic Church in the Counter Reforma 
tion, once again showed their cleverness. For in their rigidly standardized 
curriculum the Ratio studiorum that elaborately regulated Jesuit educa 
tion everywhere had been promulgated in 1599 excellent instruction in the 
ancient literatures was combined with considerable attention to Catholic 
devotions and thus, from the point of view of the Church, humanistic 
learning was prevented from becoming too secular. 

From his home at Number 6, an edifice still standing and now adorned 
with a commemorative plaque, the schoolboy Diderot would walk the few 
steps across the Place Chambeau to the Jesuit college, which stood just off the 
square at the head of a street since named for him. 32 The college was de 
stroyed by fire in 1746, but was quickly replaced by the present building 
which also bears his name. In 1770 Diderot referred to it as renowned. It 
had quite a numerous clientele, perhaps 180 or 200 in the six forms, all of 
them day students, most of them (but by no means all) from Langres, and 
coming from diverse social backgrounds, astonishing if one considers what 
was usual in the tightly knit society of the ancien regime. There were noble- 


men as well as scions of the upper and lower middle classes, and there was 
also, in Diderot s own form, the son of a tinker. 33 Throughout his life 
Diderot showed an ability to esteem men for what they were by nature rather 
than what they were by rank, and it is not impossible that the relatively 
democratic conditions of his schooling habituated him to such a point of 


Although Diderot was a sensitive child, he was also a robust one, and 
in later years he liked to recall the Spartan aspects of his early education, 
much as nineteenth-century Americans were prone to expatiate on the part 
played by the little red schoolhouse and the McGuflfey readers in making 
a nation great and keeping its manners pure. Remembering the scars of ten 
slingshot hits on his forehead, he wrote: Such was provincial education in 
my time. Two hundred boys would divide themselves into two armies. It was 
not rare for children, seriously injured, to have to be carried off to their 
parents. ... I remember that . . . my comrades and I got the idea of de 
molishing one of the bastions of my town and passing Holy Week in prison/ 
And then, carried away as he so often was by a sort of chain reaction of 
associations, and evidently remembering some childhood rival who had 
aroused his distaste, he apostrophized an imaginary Athenian who did not 
approve of an education that was so Spartan and untrammeled: *You recoil 
at the sight of their disheveled hair and torn clothes. Yet I was that way 
when I was young, and I was pleasing pleasing to even the women and 
girls of my home town in the provinces. They preferred me, without a hat 
and with chest uncovered, sometimes without shoes, in a jacket and with 
feet bare, me, son of a worker at a forge, to that little well-dressed monsieur, 
all curled and powdered and dressed to the nines, the son of the presiding 
judge of the bailiwick court. . . . They could see in my buttonhole the 
token of my attainments in study, and a boy who revealed his soul by frank 
and open words and who knew better how to give a blow with his fist than 
how to make a bow, pleased them more than a foolish, cowardly, false, and 
effeminate little toady/ 34 

Diderot was never above showing off for the girls, and one of his 
reminiscences, inspired by this theme and referring to his youthful days in 
Paris, has the incidental merit of giving us some notion of his congenital 
endowments, at least so far as muscular co-ordination is concerned. 1 was 
young, he wrote. I was in love, and very much in love. I was living with 
some fellows from Provence who danced from dusk to dawn, and from dusk 
to dawn took the hand of the girl I loved and embraced her right under my 
eyes. Add to this that I was jealous. I decide to learn to dance. From the 


Rue de la Harpe to the far end of the Rue Montmartre I surreptitiously go 
for lessons. I keep going to the same dancing master for a long time. Then 
I leave him, out of vexation over having learned nothing. I take him up a 
second, a third time, and leave off with as much vexation and with just as 
little success. What was lacking in me to be a proficient dancer? An ear 
for it? I had an excellent one. Lightness? I wasn t heavy on my feet, far 
from it. Motive? One could scarcely be animated by one more violent. 
What didn t I have? Malleability, flexibility, gracefulness qualities that 
cannot be had for the asking. 

But after having done everything to no purpose in order to learn how 
to dance, I learned without difficulty to fence very passably, and without 
any other motive than that of pleasing myself/ 35 

At his books Diderot was evidently an apt and quick pupil. Although 
in later years he became extremely critical of the value of this education, his 
youthful proficiency in it is attested by documents still extant. 36 In the 
museum at the Hotel du Breuil in Langres is a parchment certificate, or 
bene merenti, signed by the prefect of studies and probably dating from 
August 1728, in which Diderot is called an ingeniosum adolescentem who 
in public exercises had explained and elucidated passages from Quintus 
Curtius and Horace, with the praise and applause of all ( cum lauds 
plausuque omnium ). There are also in the same museum two quarto 
volumes of some six hundred pages each, a history of the Catholic Church 
in Japan by the Reverend Father Grasset, S. J., which Diderot won as 
prizes. These edifying volumes, suspiciously fresh and new, with the virginal 
appearance, even after two centuries, that books won as prizes are apt to 
have, bear inscriptions on their flyleaves indicating that Denis Diderot, 
a young man to be commended on many counts (adolcscens multiplici 
nomine commendandus ) , had received them on 3 August 1728 as a reward 
for securing the second prize in Latin verses and the second prize in transla 
tion. It is perhaps of this occasion that Diderot was thinking when he wrote 
to Sophie Volland: One of the sweetest moments of my life it happened 
more than thirty years ago, though I remember it as though it were yester 
day was when my father saw me coming home from school with my arms 
laden with the prizes I had won and around my neck the academic crowns 
that I had been given and which, too large for my brow, had let my head 
pass through. From the farthest distance that he saw me, he left his work, 
came to the door, and began to weep/ 37 

It is always interesting to seek in a mature person the abiding traces of 
his early education. In the mature Diderot one can perceive, though in an 


extremely contorted and inverted shape, the influence of the religious in 
struction imparted by his family and by the Jesuits. But much more easily 
seen, quite pellucid in the continuity of its effect upon him, is his classical 
education, reflected in the frequency of his allusions to ancient authors, ^in 
his enjoyment of the fine points of Latinity and in his fondness for in 
dulging in exegetics, in the trust he reposes in the ancient languages as a 
semantic guide, and, most important of all, in his conviction that in the 
ancient authors is to be found the acme in genius, in good manners, and in 


References to classic authors are abundant in Diderot s writings and fre 
quently go beyond the casual quotation and passing allusion to be ex 
pected in an author whose range was encyclopedic. About 1775 Diderot 
wrote for Catherine II a Plan for a University for the Government of Rus 
sia, 5 in the course of which he devoted several pages to comments about in 
struction in Greek and Latin, and incidentally showed how familiar he was 
with the idiom and manner of various classic authors. 38 He wrote of his own 
experience with the classics: Several years in succession I was as religious 
about reading a book of Homer before going to bed as a conscientious priest 
is about reciting his breviary. At an early age I sucked up the milk of 
Homer, Virgil, Horace, Terence, Anacreon, Plato, and Euripides, diluted 
with that of Moses and the prophets.* 39 And of Homer in particular he 
wrote: Let me be pardoned for the little grain of incense I burn before the 
statue of a master to whom I owe what I am worth, if I am worth any 
thing/ 40 As a result of his love of the classics, Diderot wrote a long com 
mentary on the works of Seneca; inspired and corrected a critical edition 
of Lucretius; 41 elucidated difficult passages in Horace and Virgil; 42 ac 
claimed himself as the sacristan in the church of Pliny s Latinity; 43 wrote 
an appreciative estimation (indeed, it is one of Diderot s best pieces) of 
Terence; 44 annotated and commented upon the satires of the very difficult 
Persius; 45 and composed in Latin numerous inscriptions for statues and 
public buildings. 

The abiding influence of an education founded on the classics and fre 
quently demanding the use of spoken Latin in the classroom, with a cor 
responding outlawing of the vernacular, is also revealed in Diderot s in 
teresting advice upon how to learn to read a foreign language. In his own 
article Encyclopedia, which he wrote for the fifth volume of the Encyclo- 
fedie, he declared, in speaking of linguistic and grammatical matters, that 
Nothing can be more poorly conceived for a Frenchman who knows Latin 
than to learn English from an English-French dictionary instead of having 


recourse to an English-Latin dictionary. . . . Furthermore, I speak ac 
cording to my own experience. This method turned out very well for me. 46 

Diderot s allusions to his childhood are few but full of flavor. In 1773 he 
was trying to puzzle out a difficult passage in Horace and using the evi 
dence of some very unusual words and constructions. This recalled to him 
the days of his boyhood and the circumstances of his early education. When 
I used to study Latin under the iron rule of the public schools, a trap that 
I used to set for my teacher, and one that always worked, was to employ 
these strange turns of expression. He would cry out against them, he would 
storm at me, and when he had completely committed himself, what with 
storming and crying out, I would show by a little quotation that all his 
abusive remarks applied to Virgil, Cicero, or Tacitus. 47 

The perversity of the gifted young has ever been the despair and the 
secret pride of the teacher. 


Diderot Becomes an Abbe and Goes to Paris 

A s 


s THE years went by and young Diderot flourished 
, in learning, the question naturally arose as to 
what should be his career. There was a moment, but only a moment, in 
which it seemed possible that he might follow his father s trade. For Diderot, 
impatient of the remonstrances and corrections of his teachers, told his 
father one day that he didn t want to go to school any more. 

Well, then, do you want to be a cutler? 

With all my heart. 

So he put on the workshop apron and started in by his father s side. As 
his daughter tells the story, he spoiled everything he touched, knives, pen 
knives everything. This ended in four or five days when he got up one 
morning, climbed upstairs to his room, took his books, and went back to 
school. I can stand impatience better than boredom, he said. 1 

For persons who know only the Diderot of later life a spirited and 
emphatic freethinker it will come as a surprise to learn that at the age of 
thirteen he signified in a solemn ceremony his intention of becoming a 
priest. On 22 August 1736, the Bishop of Langres conferred the tonsure on 
Denis Diderot, a rite consisting of cutting off some locks of the candidate s 
hair in the form of a cross, the while the future ecclesiastic reads some verses 
from the Fifteenth Psalm. 2 As a result of this ceremony, Diderot was en 
titled to be addressed as Abbe and was expected to wear an abb& char 
acteristic attire, which consisted not of a soutane worn by priests, but black 
smallclothes, a short mantle, and an ecclesiastical collar with its white tabs. 
Thus he became for a time a member of a very numerous class of persons 
in eighteenth-century French life, for abbes, many of whom never proceeded 
to holy orders but all of whom were eligible for ecclesiastical benefices, were 
conspicuous features of the social landscape. 


There is nothing to show that young Diderot went through this ceremony 
against his will. The timing of the ceremony, in all probability, was de 
termined by the hope entertained by Diderot s relatives that he would be 
allowed to succeed to the lucrative prebend that his uncle, Canon Didier 
Vigneron, occupied at the local Cathedral of Saint-Mammes. Perhaps be 
cause of this consideration Diderot took the tonsure at so early an age, for it 
was extremely unusual and somewhat irregular, although not precisely un- 
canonical, to undergo this ceremony before the age of fourteen. 

These hopes, however, presently foundered. Canon Vigneron found that 
his chapter objected to his being succeeded by his young nephew. To circum 
vent them the Canon went through the proper legal forms for handing over 
his prebend to the Pope in favor of Denis Diderot, tonsured cleric of the 
diocese of Langres, fourteen years and six months old, and no other. But 
five hours after he had sent his representative off to Rome, die Canon died. 
Apparently his demission was not binding unless the Pope had accepted it 
while the Canon was still alive. The chapter immediately elected someone 
else, and the hopes of that career went glimmering. 3 

Soon afterwards, Diderot, influenced of course by his teachers in the 
Jesuit college where he was becoming markedly successful, began to think 
of becoming a Jesuit himself. It may have been about this time, too, that 
he underwent the stress of a devout religious experience. His daughter states 
that for four or five months during the time that Diderot was desirous of 
becoming a Jesuit, he fasted, wore a hair shirt, and slept on straw. 4 The 
following passage from his novel James the Fatalist, written in 1773, may 
therefore be autobiographical in nature: There comes a moment during 
which almost every girl or boy falls into melancholy; they are tormented 
by a vague inquietude which rests on everything and finds nothing to calm it. 
They seek solitude; they weep; the silence to be found in cloisters attracts 
them; the image of peace that seems to reign in religious houses seduces 
them. They mistake the first manifestations of a developing sexual nature 
for the voice of God calling them to Himself; and it is precisely when nature 
is inciting them that they embrace a fashion of life contrary to nature s 
wish. 5 It is piquant to learn that Diderot went through such a religious 
crisis, because in later life he is always assuming the pose, like Lucretius ip. 
the beginning pages of De Rerum Natura, of freeing men from fear of the 
gods. Yet even in these later years he now and again felt the tug of a 
previous persuasion. For instance, he wrote in 1765 of the necessity, in per 
petuating a doctrine and an institution, for having concrete symbols that 
appeal to the imagination through the senses, and he gives as an example 


the exaltation of the multitude at a Corpus Christi processional, an exalta 
tion that sometimes lays hold of even me. I have never seen that long file of 
priests in their sacerdotal robes, those young acolytes garbed in their white 
albs, girt up with their wide blue sashes, and casting flowers before the 
Holy Sacrament; the crowd that precedes and follows them in a religious 
silence; so many men with their heads bowed down to earth; I have never 
heard that solemn and affecting plain song of the priests, affectionately re 
plied to by an infinity of voices of men, women, girls, and children, without 
my feelings being deeply moved and without tears coming to my eyes/ 6 

Apparently it was young Diderot s desire to join the Jesuits that led to 
his departure from Langres for the rest of his schooling. His daughter, 
Mme de Vandeul, declares that Diderot intended to leave surreptitiously 
in company with a Jesuit, but that his father, warned by one of Diderot s 
cousins, waited up on the appointed night and made an unexpected appear 
ance just as Diderot was creeping down the stairs. To the question as to 
where he was going at this midnight hour, Diderot replied, To Paris, where 
I am bound to enter the Jesuits. 

It won t be tonight, though your desires will be accomplished. But first 
let us get some sleep. 7 

It is a little hard to believe that an order of the dignity of the Jesuits 
would recruit its members quite so melodramatically. Mme de VandeuPs 
extremely valuable account of her father, written in the year of his death, 
can frequently be proved aberrant in details, although it is so accurate 
in the main that she has become the ghost writer of many a later biography 
of Diderot, Her source of information was of course her father, who was not 
the sort of man to mar a tale in the telling. There may be some exaggeration 
in this anecdote, just as there is in the statement that he gravely made in 
an article written for the Encyclopedic claiming that his grandmother had 
had twenty-two children, and by the time she was thirty-three years of age! 8 
A personal acquaintance named Taillefer published an account of Diderot 
only one year after his death, and though this document, too, must be 
taken with caution, the Taillefer and Vandeul accounts provide some op 
portunity for reciprocal control. With reference to Diderot s joining the 
Jesuits, Taillefer says nothing of any attempted flight from Langres. 

There is something of a mystery here. Indeed, it may even be that Diderot 
had fallen out with the Jesuits and that this caused him to go to Paris 
for the balance of his education. Evidence for such a view is found in 
something written by Jacques-Andre Naigeon, the familiar of Diderot 
during the last twenty years of his life and his would-be Boswell. In the 


year o Diderot s death, Naigeon asked Diderot s daughter and her husband 
for information about e the quarrel with the Jesuits, the context perhaps 
implying that this occurred before he went to Paris. M. Naigeon desires 
to write the life of M. Diderot/ wrote the son-in-law, [and] persecutes me 
to give him an exact and very detailed memorandum of the precise date 
of his birth and the principal events of the philosopher s youth, of his early 
studies, of his leaving the college, of the quarrel with the Jesuits, of his 
age when he was sent to Paris, how many years he stayed at the College 
d Harcourt, how many at the College de Bourgogne, and with the lawyer 
M. Clement de Ris, his adventures with Mme Frejacques, Mile La Salette, 
etc. . . . 10 We should like to know more about that quarrel with the 
Jesuits and when it occurred. As it stands, it is just another one of the little- 
known incidents in a career which was often and surprisingly inscrutable. 

At all events and for whatever reason, Diderot left Langres for Paris, 
probably in the autumn of 1728, but possibly in 1729, his business being to 
finish his last year of study, his rhetoric/ in what would now be called a 
lycee.^ Thus began the great adventure, the first going-away-from-home. 
There is no indication of his being reluctant to leave Langres, save perhaps 
for some sentimental thoughts about Mile La Salette (a Langres girl born 
the same year as he and who, in the course of years, became the mother of 
the man who was to marry Diderot s daughter), or about another, but 
unidentified, girl of Langres who made a sufficiently lasting impression to 
cause him to mention her in a letter to Sophie Volland thirty years later. 12 
His father accompanied him. Down the valley of the Marne they rode 
my melancholy and tortuous compatriot, the Marne/ he later called it 13 
traveling, if they went by the slow coach, seven days to reach Paris. 14 

At Paris, Diderot s father made the necessary arrangements for his son s 
settling into school, took his leave as though he were going to depart 
from the city, and then stayed on in Paris a fortnight just to make certain 
that all was going well. Having then been reassured by young Diderot that 
he was happy and wanted to stay, and by his son s principal that the boy 
was an excellent student even though they had had to discipline him, the 
father went back to his knives and lancets at Langres. These incidents are 
completely in character, both for father and son. For young Diderot had 
thoughtlessly and big-heartedly undertaken to do someone else s work. He 
obliged a disconsolate fellow-student who was reluctant to address himself 
to the assignment of putting the serpent s seductive speech to Eve into Latin 
verse. Diderot s verses were good too good to have been done by the lad 
who was supposed to do them. Both students were very roughly handled/ 


wrote Mme de Vandeul, and my father gave up others business to occupy 
himself henceforth exclusively with his own/ 16 

A new phase of his career had begun and a lasting one, for he was to 
be a Parisian to the end of his days. 

* ***** 

From the time when he was about sixteen and went to Paris until the 
time when, at twenty-nine, he was already embarked on a career of letters 
and was desirous of getting married, little is precisely known of Diderot 
and of where and how he spent his time. This period of his life is a docu 
mentary desert, filled with shimmering mirages of assertion and whimsy, 
with widely spaced waterholes of verifiable fact upon which the panting 
searcher stumbles when just about to expire. By the year 1742 it becomes 
possible to follow his career with some certainty, but meanwhile some 
thirteen of the most important formative years of his life are shrouded and 
obscure. Diderot himself seldom spoke of them and, indeed, seems almost 
intentionally inscrutable about this period. It is amazing that no memoir 
writer contemporary with Diderot was able to recollect a youthful acquaint 
ance with a man who was constantly resident in the nation s capital and who 
subsequently became so famous. Yet neither friend nor enemy has spoken 
from certain, personal knowledge of these years. The earliest notice of him 
recorded by a contemporary refers to the year 1742. 

This account occurs in the memoirs of Johann Georg Wille, a German who 
lived most of his life in Paris and became one of the most celebrated en 
gravers of the century. His likeness is preserved for us in a magnificent 
portrait by Greuze, which Diderot himself pronounced to be very beauti 
ful and very like. 16 In the year in which they met, Wille rented lodgings 
in the Rue de TObservance, now called the Rue Antoine-Dubois, a very 
short street which at one end ascends by a stairway to the Rue MonsJeur-le- 
Prince and on the other looked out on the College de Bourgogne, the site 
of which is now occupied by the Ecole de Medecine. 1 was curious to know 
who might be my neighbors in the house/ wrote Wille, c and, in order to 
find out, I went downstairs to my landlord s rooms where by chance I found 
a very affable young man who in the ensuing conversation informed me that 
he was seeking to become a proficient man of letters and a still better phi 
losopher, if that was possible; he added that he would be very happy to 
make my acquaintance, the more because he esteemed artists and loved the 
arts, because he thought we were of the same age, and because, moreover, 
he already knew that we were neighbors, I gave him a handclasp and from 
that moment we were friends. This young man was M. Diderot, since be- 


come famous. He occupied the entresol the floor beneath me, had a beautiful 
library there, and with pleasure lent me the books that might give pleasure 

to me. 5 17 

This makes an engaging and attractive picture. A present-day reader, 
knowing that this is the picture of a young man about to enter a prodigious 
career of intellectual virtuosity, and realizing how little is known of the 
previous formative period, when this mind was broadening its range and 
deepening its mastery, is tantalized by this fleeting view into those misty 
years. What experiences had Diderot had to engender and confirm these 
tastes in philosophy and the arts ? How much formal schooling had he had, 
and in what institutions of learning? How had he supported himself or 
been supported during all this time? 

Even the school he entered on coming to Paris is a matter of conjecture. 
The evidence is conflicting and confused. A much younger contemporary 
says that Diderot entered the famous College Louis-le-Grand, the school 
where Voltaire was educated and whose imposing buildings still stand, just 
across the Rue Saint-Jacques from the Sorbonne. 18 Diderot s daughter and 
Naigeon declare that he entered the College d Harcourt on the Boulevard 
Saint-Michel, just across from the Place de la Sorbonne, where the Lycee Saint- 
Louis now stands. 19 But his daughter also says that he was a school chum 
of the future Cardinal de Bernis, who indubitably was a student at Louis-le- 
Grand. 20 This conflicting testimony has touched off a controversy among 
scholars, nurtured by the fact that the Colleges records for those years are 
no longer extant. One authority even argues for the College de Beauvais. 21 
The recently published inquiry made by Naigeon of Diderot s daughter and 
son-in-law in 1784, previously alluded to, would seem to settle the matter 
in favor of the College d Harcourt, but opens up an entirely new vista in 
suggesting that Diderot was also a student at the College de Bourgogne. The 
matter may be summarized by saying that it is extremely improbable that 
Diderot attended Louis-le-Grand exclusively, if he attended it at all. He 
probably went to the College d Harcourt instead, but he could very possibly 
have attended both. 

The point is more important than it may seem at first. If it were possible 
to know with certainty to what college in Paris Diderot belonged, then one 
could know whether in the important years when he was being introduced to 
formal philosophy, studied according to the scholastic method with its em 
phasis on metaphysics and categories and universals and with its strong 
tincture (at that time) of Cartesianism, he was being taught to see things 
from the Jesuit or the Jansenist point of view. For Louis-le-Grand was a 


Jesuit college, whereas the College d Harcourt was an active center of 
Jansenism. 22 Those who dip into the study of seventeenth- and eighteenth- 
century France quickly become aware that a chronic struggle went on within 
the Catholic Church between these two factions. Moreover, in a society 
where Church was as closely knit with State as it was during the ancien 
regime, these theological disagreements had grave political repercussions. 
In the early and middle eighteenth century it was scarcely possible for any 
thinking Frenchman to avoid taking a position, even though publicly un- 
avowed, in these disputes. Jansenist and Jesuit cordially hated each other, 
and freethinkers scoffed at both. 

The Jansenists took their name from Cornelis Jansen (1585-1638), Bishop 
of Ypres. They constituted a puritanical and fundamentalist sect within 
the Catholic Church, which by the time of the latter years of Louis XIV 
seemed to be losing out to the Jesuits. The King, seeking uniformity and 
orthodoxy, asked the Pope to settle the dispute once for all. The answer was 
the papal bull Unigenitus, promulgated in 1713, which declared heretical 
101 propositions set forth in a popular Jansenist book of devotions. But in 
stead of settling the dispute, the bull only served to inflame it. The Pope s 
action was resented by many as too great an interference in French domestic 
affairs. Nevertheless, the energetic measures of the government to secure 
acceptance of the bull forced the Jansenists undercover. They even published 
an underground newspaper, Les Nouvelks EccUsiastiques, which, in spite 
of the determined efforts of the police, appeared with mocking and impish 
regularity right up to its discontinuation in 1803. Ascetic and dour, stubborn 
in adversity and embittered by it, the Jansenists were not the most broad- 
minded people of their time. Both sides shocked the liberals of the century, 
who feared the authoritarian proclivities of the one as much as those of 
the other. 

Which group, then, shaped Diderot s thinking during his college years? 
Inasmuch as it is known that he was awarded the degree of master of arts in 
the University of Paris on 2 September 1732, indicating a formal schooling 
of some years duration at Paris, it is possible to argue that Diderot trans 
ferred from the one college to the other following his rhetoric* and before 
his philosophy. 2 * This conjecture has the advantage of reconciling con 
flicting accounts. It makes it possible for Diderot to have known the future 
Cardinal Bernis at the Jesuit Louis-le-Grand, as Mme de Vandcul says he 
did, and to have sat there under the famous teacher, Father Poree, as Diderot 
claims in his Letter on the Deaf and Dumb, and still to have been a student 
at the Jansenist College d Harcourt, as his daughter and Naigeon declare 


he was. 24 Yet another purpose can be served by this convenient conjecture. 
Diderot s general editorial policy, as well as the articles he himself wrote for 
the Encyclopedic, reveal a very considerable familiarity with exegetics, but 
without any special fondness or predilection for them. Therefore, could not 
the hypothesis that he attended both Jesuit and Jansenist colleges lead to 
the further one that, having become familiar with the point of view of 
each, he found himself repelled by both, so that instead of inclining him to 
the one or the other, each canceled the other out? 

What he did immediately after receiving the master of arts degree is no 
less uncertain. Although it has generally been presumed that he thereupon 
discontinued his formal schooling, there is nothing in the evidence that de 
mands that this be so. The account his daughter gives of his adventures 
implies that by this time Diderot, if he ever had the intention of studying 
for the priesthood, had given it up. This, too, tallies with Naigeon s testimony 
that while Diderot was a student at the College d Harcourt he stopped wearing 
his ecclesiastical attire. 25 Documents show that twice during this crepuscular 
period of Diderot s life he considered entering the law, one document re 
ferring to the year 1736 and the other to about i7 4 i. 26 Mme de Vandeul s 
account is probably accurate as far as it goes, although the biographer might 
well wish, with a sigh, for greater precision in dates: His studies completed, 
his father wrote to M. Clement de Ris, a solicitor at Paris and a fellow 
townsman, to take him into the household and have him study law. He 
stayed there two years; but the searching of deeds and the listing of in 
ventories had few attractions for him. All the time he could steal from his 
employer was used in studying Latin and Greek, which he thought he did 
not sufficiently know; mathematics, which he always passionately loved; 
Italian, English, etc. Finally he gave himself up to his taste for letters to 
such a point that M. Clement felt he ought to inform his friend of the poor 
use his son was making of his time. Thereupon my grandfather expressly 
charged M. Clement to propose a profession to his son, to induce him to 
make his choice promptly, and to engage him to be a doctor, a solicitor, 
or a barrister. My father asked for time to think it over, and was granted it. 
After some months, the propositions were renewed. Then he said that the 
profession of doctor did not please him, he did not want to kill any one; 
that the profession of solicitor was too difficult to perform scrupulously; 
that he would gladly choose the profession of barrister, save that he had an 
unconquerable aversion to busying himself all his life with other people s 

* "But," said M. Clement to him, "what do you want to be, then?" 


"Ma foi, nothing, nothing at all. I like study; I am very well off, very 
happy; I don t ask anything else." Thereupon Diderot s father cut off his 
allowance and demanded that he either choose a profession or come home 
within the week. Diderot left the house of the solicitor, so as not to put 
him to any expense, and, says Mme de Vandeul, lived the next ten years on 

his own. 27 

At some time during this decade Diderot was a tutor in the household of 
a wealthy financier named Randon. But Diderot was not of the temperament 
to enjoy such confining work: "Monsieur, look at me. A lemon is less 
yellow than my complexion. I am making men of your children, but each 
day I become a child with them. I am a thousand times too rich and too 
well off in your house, but I must leave it. The object of my desires is not 
to live better, but just not to die." J 2S 

All this is completely in character and entirely credible. It shows Diderot s 
love of independence, his hatred of constraint. And it shows, too, a sort of 
lack of fondness for children which is also to be seen or sensed in his writings, 
even though he once asserted in middle life that he was very fond of old 
men and children. Diderot was constantly letting his feelings pour forth 
in jets of enthusiasm, but one can look long and far that one instance 
excepted for him to express any great enthusiasm for children and child 
hood, except, of course, his own. 29 And not even his own daughter seems to 
have interested him much until she began to make precocious remarks which 
gave him hope that she possessed an interesting and original mind. He seems 
to have pitied the state of childhood its helplessness, its limited outlook, 
its wrong conclusions logically derived from false premises but he did not 
admire it. 

Aside from two years accounted for at the solicitor s and three months 
being a tutor at the financier s, Diderot, according to his daughter s account, 
was on the town. He passed ten whole years . . having no other resource 
than those very sciences that were earning him the disapprobation of his 
father. He gave lessons in mathematics; if the pupil was quick ... he 
would teach him the whole day long; but if he found a stupid pupil, he 
would not go back. He was paid in books, in furniture, in linen, in money, 
or not at all; it was all the same to him. He wrote sermons. A missionary 
ordered six from him for the Portuguese colonies and paid fifty cu$ apiece 
for them. My father thought this affair one of the best he ever brought off.* so 

This testimony bespeaks a precarious existence. Now and again he was 
able in other ways to supplement the income he derived from giving lessons. 
For example, he tells us that he prepared the general formula and mathe- 


matical tables for a treatise published in 1741 on gnomonics, the science of 
sundials. 31 This task presupposes considerable mathematical competence 
and accuracy, and it is to be presumed, although not certainly so, that he 
was paid for it. Moreover, the censor s approbation of Diderot s translation 
of Temple Stanyan s Grecian History, dated 25 May 1742, proves that he 
had prepared the manuscript before that time, and for this translation he 
probably received something in advance. 32 Still, his was evidently a Bo 
hemian, hand-to-mouth existence, provided that, as will be discussed later, 
he did not spend some of these ten years in formal theological studies. 
Diderot s daughter is emphatic that her grandfather sent no money to his 
recalcitrant son, although his mother, more tender and more compliant, 
sent him some louis, not by the post nor by friends, but by a maid servant 
who did the sixty leagues on foot, delivered to him the small sum from 
his mother, adding to it, without mentioning it, all her own savings, and then 
walked back the sixty leagues in return. This woman carried out this com 
mission on three occasions. 83 

With an income so uncertain and evidently operating in geyserlike intervals 
of fast and feast, it is not surprising to learn that sometimes his cupboard 
was bare. One Shrove Tuesday, a day when, like Christmas in America, 
absent youths were particuarly likely to be homesick, Diderot arose to find 
that he had absolutely no money with which to buy dinner. Not wanting 
to disturb his friends upon such a day, he tried unsuccessfully to work, and 
then went out for a long walk. He came back to his tavern; upon entering, 
he sat down and felt ill. The landlady gave him a little toast soaked in wine, 
and he went to bed. "That day," he told me, "I swore that if ever I possessed 
anything, never in my life would I refuse something to an indigent person, 
in order not to condemn any fellow man of mine to put in a day as dis 
tressing as that." 34 

Diderot was not averse to receiving aid from fellow townsmen, knowing 
that his father would pay up. There is documentary evidence of this having 
occurred in 1736. On 20 August of that year, a man formerly from Langres 
named Foucou fifteen years later Diderot acknowledged in his Encyclo- 
fSdie article on Steel the helpful information contributed by M. Foucou, 
previously a cutler signed a receipt for thirty-eight livres received from 
Diderot s father by the hands of Brother Angel, a Barefooted Carmelite 
friar. On the same receipt Didier Diderot wrote: This is the final receipt 
of the amount agreed upon with M. Foucou of Paris. I wrote him on 23 
May 1736 not to advance anything to Diderot nor to take him into his 
house; that he ought to remain with the solicitor. . . . Therefore there will 


be no making it up to him [Foucou] if he [Diderot] stays with him at all, 
for it is against my wishes. 1 35 

Need sometimes brought Diderot close to roguishness. Mme de Vandeul 
tells a long story of how Diderot convinced Brother Angel, the Carmelite 
friar mentioned above, a man who also came originally from Langres and 
was a distant relative of the Diderots, that he intended to become a friar m 
Brother Angel s monastery. On that understanding Diderot received pay 
ments amounting to some two thousand livres. When at last Brother Angel 
showed that he would advance no more, Diderot said to him, Brother 
Angel, then you don t want to give me any more money?" 

1 "Assuredly not." 

"Well, then, I don t want to be a Carmelite any more. Write to my father 
and get yourself paid." 36 Both Diderot and his daughter thought this sort 
of panhandling clever. 

During the nine or ten years between the time of receiving a master of 
arts degree at the University of Paris and his writing the earliest of his 
letters now extant, Diderot existed in what to posterity has seemed a 
penumbra of obscurity. But the person whom Wille found so attractive has 
left scattered in his works various allusions to his tastes and to his doings 
in those early years, which help in some measure to answer the question of 
what manner of man he was on the eve of his public career. In the first 
place, it is probable that his greatest single intellectual competence lay 
at that time in the field of mathematics. When he published in 1748 his 
highly respected Memoires sur differens sujets de mathimatiqucs, he wrote 
in the Fifth Memoir, in which he made some corrections in Newton s cal 
culations of the effect on pendulums of the resistance of air: It is true that I 
studied Newton with the intention of elucidating him; I shall even con 
fess to you that this work was pushed on, if not with great success, at 
least with adequate vivacity; but that I no longer gave it a thought from 
the time that the Reverend Fathers Le Seur and Jacquier published their 
Commentary [1739], and I have not been tempted to take it up again.* 3T 

In the second place, his random recollections show that during these early 
years he haunted the theater and was much enamored of acting -and 
actresses. Evidently, too, he deemed it possible that he could have made his 
living on the stage: *I myself, when I was young, hesitated between the 
Sorbonne and the Comedie. In winter, in the worst sort of weather, I used 
to recite roles from Moliere and Corneille out loud in the solitary walks of 
the Luxembourg. What did I have in mind? To be applauded? Perhaps. To 
live on familiar terms with women of the theater, whom I found infinitely 


lovable and whom I knew to be of very easy virtue? Assuredly. I don t know 
what I wouldn t have done to be pleasing to la Gaussin, who made her 
debut about that time and who was beauty personified; or to la Dangeville, 
who had so many attractive qualities on the stage. 38 

The excitement that young Diderot found in going to the theater is well 
depicted in a passage that he wrote in 1758: Fifteen years ago our theaters 
were places of tumult. The coolest heads began to get heated upon entering 
them, and grave men shared there, more or less, the transports of giddy 
ones. . . . People moved about, fidgeted, jostled one another, one s soul 
was quite beside itself. . . . The piece began with difficulty and was often 
interrupted, but let a fine passage come along and there was an incredible 
tumult, encores were demanded endlessly, and people enthused over the 
actor and the actress. The enthusiasm passed from the pit to the dress circle, 
and from the dress circle to the boxes. People had come with ardor, they 
left in a state of intoxication: some went to visit the girls, others scattered 
themselves in society; it was like a thunderstorm which passes over, spending 
itself afar, but the mutterings of which last a long while after it has passed 
by. That is what pleasure is like/ 39 

Sometimes, as Diderot recalls in his Letter on the Deaf and Dumb, his 
interest in the stage was a little more philosophical and shall we say 
unconventional: Formerly I used to visit the theater very often, and I knew 
most of our good plays by heart. On the days when I proposed to study 
movements and gestures, I went to the third-class boxes, for the farther 
I was from the actors the better I was placed. As soon as the curtain went 
up ... I would put my fingers into my ears, not without some astonish 
ment on the part of those round about me ... and stubbornly kept my 
ears stopped up as long as the action of the actor appeared to me to be in 
harmony with the lines that I was remembering. I listened only when I 
was thrown off the track by the gestures on stage, or thought I was/ And 
Diderot recalled with amusement the redoubled surprise of the people 
round him when they saw me shed tears in the pathetic parts, and that with 
my ears continuously stopped/ 40 

As a footnote to his love for the theater and his love of ideas, it may 
fairly be conjectured that Diderot often visited the Cafe Procope, for until 
1770 the old Comedie-Franfaise was located just across the street. The 
Procope, then a famous center for actors, playwrights, academicians, and 
other men of letters, is now reopened and operating at the old stand, 13, 
Rue de PAncienne Comedie. In its eighteenth-century heyday it was fully 
as famous as the Dome and the Rotonde in the youthful days of Hemingway 


32 j- 

and Ezra Pound or the Caffi de Flore when Sartre was frequenting it, and it 

seems hardly possible that Diderot was not among the Procope s patrons. 

From scattered allusions in his later works, we can get some impression 
o Diderot s manner and appearance at this time. He was a young man of 
large frame -a friend later said of him that he was built like a chair-man 
or porter 42 - and well set up. He wore his own hair, which was blond, heavy, 
and thick, and he was, then as always, careless of dress, for he recalls in his 
Rameau s Nephew the days when he gave lessons in mathematics and wore 
an overcoat of gray shag, all played out on one side, with one of the sleeves 
torn- and black woolen stockings mended at the back with white thread/ 43 
Moreover, he evidently liked to tease the girls: as he looked at Greuze s 
portrait of Mme Greuze, exhibited in the Salon of 1765, Diderot remembered 
when she was a girl in her father s bookshop on the Quai des Grands- 
Augustins, bordering the Seine. Diderot entered the shop one day, with 
that lively, ardent, and daft manner I used to have. 

"Mademoiselle, La Fontaine s Fables, and a Petronius, if you please/ 

"Here they are, Monsieur. Are there any other books you d like?" 

"I beg your pardon, Mademoiselle, but . . ." 

"Don t be hesitant." 


"Fie! Monsieur; do you suppose that one keeps in stock, that one reads, 

nasty things like that?" 

* "Why! why! is that a nasty book, Mademoiselle? I didn t realize that!" 44 
Finally, it may be conjectured with some assurance that Diderot took love 
where he could find it, a conclusion that might be drawn from his account, 
written in 1758, of an incident that would seem to have occurred in these 
early years: Oh! my dear friend, where is the time when I had long hair 
floating in the breeze? In the mornings, when my nightshirt collar was open 
and I took off my nightcap, my hair fell in great, disordered locks over 
well-knit and very white shoulders; and my neighbor would get up early 
in the morning from her husband s side, half-open the curtains of her 
window, intoxicate herself with the sight, and I would readily perceive 
what was going on. Twas thus that I seduced her from one side of the 
street to the other. When I was with her, for we came together at last, I 
acted with candor and innocence, with a manner gentle, simple, modest, 
and true. All has passed away, the blond hair, and the candor, and the 
innocence. 45 
Diderot, it may be remarked, was always quite adequately appreciative 


of female charms. He was not, however, an unbridled libertine, even if the 
principal bridle was nothing more virtuous than a horror of venereal disease. 
He recalls, in a letter to Sophie Volland, how he escaped providentially from 
running the risk of it on two occasions that must date from these early 
times. I never think of it without having goose flesh/ he wrote. 46 

Now, what about the possibility, preposterous though it seems, that Diderot 
spent some time as a graduate student of theology? By his own statement, 
he was balancing between the Sorbonne and the Comedie not long after 
Mile Gaussin made her debut at the Comedie-Frangaise, an event which took 
place on 28 April 1731. Diderot s reference to the Sorbonne was, of course, 
to the faculty of theology of the University of Paris, and it certainly is true 
that his degree of master of arts qualified him to take up advanced theological 
studies if he chose. Diderot says he wavered between a theologian s career 
and an actor s, and since the context of the passage shows that he did not 
go on the stage, it follows that it is possible that for a time he became instead 
a graduate student in theology. If only the register books of the faculty of 
theology were extant but unfortunately they have disappeared. 47 

It should be recalled that Diderot was only nineteen years old when he re 
ceived his master of arts degree, and it therefore seems unlikely that his 
Father would have allowed him to go completely on his own. Of course, two 
Df these years were spent, according to the family tradition, as apprentice 
to a solicitor. But were they the two years immediately following the con- 
cerral of his degree in September 1732? Probably not, for Diderot s father, 
writing in May 1736, says that Diderot ought to remain with the solicitor. 
^Jow, even if two of those intervening years had already been spent at the 
solicitor s, there is still a hiatus of some twenty months to be accounted for. 

A statement in his father s will also gives color to the supposition that 
roung Diderot spent more years living off money sent him by his parents 
han Mme de VandeuFs story credits, for in that document, drawn up in 
750, Didier Diderot remarks: Tou well know, you, Diderot the elder [son], 
he great expense I have been to for you these twenty years that you have 
een at Paris. If I added up nothing but what is of my certain knowledge, I 
ave sent you more than ten thousand livres, not including what your 
lother and your sisters sent you and the interest on this sum. . . . 48 Now, 
fhen it is recalled that board, room, and tuition at a place like Louis-le- 
hrand was only four hundred livres a year, it is easy to see that the purchasing 
ower of ten thousand livres could account for quite a few years in a student s 
fe. 49 Considering Diderot s relative youth, it seems not unlikely, therefore, 


that he continued his schooling after 1732, possibly in theology; that per- 
haps if he did, he became disgusted with theological studies; and that then 
he and his father turned to the possibility of his becoming a solicitor. 

Far more startling and sensational, however, is the probability that as 
late as about 1741 Diderot was seriously intending to become a doctor of 
theology. He himself alluded to it in a passage he wrote in the Salon of 1767. 
<I arrive in Paris, 5 he wrote. I was going to take the fur and install myself 
among the doctors of the Sorbonne. I meet a woman beautiful as an angel. 
I want to sleep with her. I do so. I have four children by her and there I 
am forced to give up Homer and Virgil, whom I always used to carry with 
me in my pocket; the theater, for which I had a fondness; very lucky to under 
take the Encyclopedic, for which I shall have sacrificed twenty-five years of 

my life. 50 

This passage needs explanation. In the first place, naming the Sorbonne 
was the usual way of referring not to the whole University of Paris, but 
only to its faculty of theology. In the second place, to take the fur was a 
locution that signified taking a university degree more advanced than the 
master of arts. 51 In the third place, to become a doctor of theology at the 
Sorbonne, one had to be a priest and have completed five years of theological 
studies after receiving the master of arts degree. 52 In the fourth place, 
Diderot did not meet his future wife before 1740 at the earliest. The nub 
of the problem, then, is this: is it possible to lend credence to the astonishing 
view that Diderot was engaged in, or at least intended to embark upon, 
advanced theological studies at as late an age as twenty-eight or twenty- 
nine? If so, it is a fact his daughter either did not know or took pains to 


Diderot s writings, especially his articles in the Encyclopedic, reflect great 
familiarity with theological sources and concepts, and this fact has been 
claimed as clear proof that he had engaged in advanced theological studies, 53 
But although it is evident that Diderot could quote the Church Fathers 
with as much appositeness and skill as Anatole France and certainly knew 
his theology well enough not to blunder unwittingly into the innumerable 
pitfalls and booby traps of the thickly mined areas of theological contention, 
still the more we examine his writings, the less we feel justified in accepting 
this as incontrovertible proof of advanced study. A person hostile to Diderot 
might say of him, as Gibbon said of Saint Augustine, that his learning is 
too often borrowed and his arguments are too often his own. Therefore, the 
indirect argument, that internal evidence attests the advanced state of Diderot s 
theological studies, has some plausibility but is not incontestable. 


More material evidence is found in letters sent from Paris by Pierre La 
Salette of Langres. After writing on 10 August 1741 that the shirts Diderot 
had received from Langres were quite unsuitable. La Salette wrote again 
eight days later: He needs linen, the dear son! As for the rest, he is well 
fitted out for from now to i January, the time that he has reiterated to me 
for the execution of his promises/ 54 La Salctte s next letter, dated 4 Septem 
ber 1741, once more harps on linen, but it also reveals the nature of Diderot s 
promises: He has let me come to the conclusion that it would be better 
to send him the cloth for making shirts and collars instead of sending him 
the shirts and collars ready-made. I have examined his linen. He simply 
must have some: he was obliged to have the shirts that his dear mother sent 
him remade. . . . For the rest, he is very well and perseveres in his promises. 
Saint-Sulpice will be his residence on i January next. May God grant him 
the grace to carry it out for the satisfaction of his family, since it is the 
profession that he chooses and which no one has urged him to take in 
preference to all others. 55 

These references to promises suggest that Diderot really was thinking of 
an ecclesiastical career when he met his future wife. The celebrated Paris 
seminary of the order of Saint-Sulpice, founded in 1641 and situated just 
opposite the famous Parisian church of that name, was at that time the best 
known and most popular seminary in France for the training of priests. 
Not organized as a monastery, its object was to prepare young clerics for 
holy orders and concomitant ecclesiastical functions. So prominent was it 
that, according to the Catholic Encyclopedia, When the Revolution broke 
out the seminary of Paris alone had trained more than five thousand priests, 
and more than half the bishops who faced that dreadful tempest (about 
fifty) had been in Sulpician seminaries. 

In the passage from the Salon of 1767, Diderot spoke of being a doctor 
at the Sorbonne and did not mention the Seminary of Saint-Sulpice, of which 
Pierre La Salette wrote in 1741. Are these two bits of testimony therefore 
irreconcilable? Almost assuredly not; for, as we have already seen, one 
had to be an ordained priest to qualify for the doctorate of theology, and 
there was a close connection between the Sorbonne and the Seminary of 
Saint-Sulpice. This is demonstrated by a pertinent passage from one of the 
classics of French literature, published in 1731. In the History of Manon 
Lescaut, written by a man who was himself an abbe, the faithless Manon 
watches the young seminary student from Saint-Sulpice undergo his public 
examination in the school of theology at the Sorbonne. 56 

It may be concluded, then, that Diderot really intended about the year 


1741 to take up an ecclesiastical career. There is no evidence, however, that 
he ever actually did enter the Seminary of Saint-Sulpice, only evidence that 
he said he intended to. Nor is there any evidence whatever that he xvas 
eager to enter this profession. On the contrary, he tells us in an autobio 
graphical passage written in 1773 or 1774 that in the classes of the University 
my masters could never conquer my disdain for the frivolities of Scholasti 
cism/ He devoured books of arithmetic, algebra, and geometry, he tells us, 
and took pleasure in Homer, Virgil, Tasso, and Milton, but always coming 
back to mathematics, as an unfaithful husband, tired of his mistress, returns 
from time to time to his wife! * 67 

This analogy, as characteristic of eighteenth-century manners as it was 
of Diderot himself, seems to show that if Diderot intended to become a 
priest, it was not precisely because he had what the Methodists term a 
call/ On the other hand, there is no evidence that at this early time in his 
life he was yet in flaming rebellion against the Church. It was not until 
years later that the necessities of philosophical consistency turned him against 
Christian belief. And it is quite possible that he contemplated the priest 
hood without either eagerness or reluctance. After all the ahM, supported 
by some benefice or commendam which provided for an untrammelcd life 
in secular society, was a very prominent element in the eightecwh<emury 
French scene. Perhaps, then, Diderot hoped to secure a benefice or sinecure 
that would allow him to enjoy both security and the pleasures of scholar 
ship; perhaps he was impressed by the fact that after all two priests were at 
that very moment publishing their monumental commentary cm Newton; 
perhaps he was ready at last to give up his precarious and necessitous inde 
pendence. At all events, meeting the girl whom he wanted to marry caused 
him to lay aside any plans he may have had for a career in which celibacy 
was a prerequisite, and presently Diderot was once again being urged fay 
his family to enter the law office of a solicitor. 


Clandestine Marriage 


WAS about this time, in 1741,* wrote Mme de 
Vandeul in her memoir of her father, that he 
made the acquaintance of niy mother/ l 

At this period Anne-Toinette Champion, who was bom at La Ferte- 
Bernard on 22 February 1710, and was in consequence three and a half years 
older than her future husband, was living with her widowed mother in 
very modest and straitened circumstances. 3 The family was a respectable 
one, even though stricken by indigence, Mme Champion, a widow with no 
property/ continued Mme de Vandeul, came to Paris with her daughter, 
then three years of age, A childhood friend of my grandmother gave her a 
place to stay, and my mother was put into the convent of the Miramiones 
in order to learn to work with sufficient skill to have no need of the assistance 
of anyone/ s At sixteen, she settled with her mother in a small apartment, and 
both of them carried on the business of dealing in lace and linen. . . My 
mother was tall, beautiful, pious, and modest* Various traders had wished 
to marry her; but she preferred her work and her liberty to marrying a 
husband whom she could not love* 

*My father * . , saw her and wanted to see her again. . . As he could 
not pay his attentions so assiduously to my mother without some reason, 
he told the ladies that he was destined to become an ecclesiastic; that soon 
he would enter the Seminary of Saint-Nicolas; that he had need of a certain 
provision of linen, and he besought them to take charge of the matter/* 

It docs not require a professional detective to deduce some close connection 
between the collars and shirts that Diderot persuaded Pierre La Salctte 
had to be done over and the fact that the Champion ladies were in that sort 
of business. Diderot s courtship* as a matter of fact, was an anticipation of 
the Hollywood boy-meets-girl formula, as he himself, in his later play 
wright days, seemed to realize. 10 his Father of a family, Diderot turned a 



3 8 

fond and Narcissan gaze upon recollections o his earlier self. The reck 
less and impetuous Saint-Albin was modeled, Diderot told his daughter, 
on the young man who had courted Anne-Toinette. 5 

It is a matter of interest, almost astonishment, that Diderot was able to 
convince so many people on so many occasions that he intended to become 
a priest or a monk. In Langres, while still a lad, he intended to become a 
Jesuit; in Paris, he convinced Brother Angel of his intention to join the Bare 
footed Carmelites; in 1731 or 1732, according to Diderot s recollections 
recorded in a letter to Sophie Volland in 1765, he was willing to become a 
Carthusian monk, although on this occasion, it is true, the prior did not take 
him at his word; 6 in 1741 he persuaded La Salette that he intended to enter 
Saint-Sulpice, while at nearly the same time he was leading the Champions 
to believe that he was about to enter the Seminary of Saint-Nicolas-du- 
Chardonnet, a nearby and highly regarded training school for priests where 
Ernest Renan was to be a student a century later. From all these incidents 
we must conclude that Diderot not only had a convincing way about him 
but was also so familiar with seminary ways and various religious orders as 
to sound completely plausible. 

Their married years were to prove, abundantly and regrettably, that Denis 
Diderot and Anne-Toinette Champion were far from temperamentally 
congenial. What was it about her, then, that so appealed to Diderot in the 
days of his courtship? The question is, it must be confessed, a silly one. What 
appeals to any young man in a girl beautiful as an angel* ? But it is also 
possible that Diderot, already thirteen or fourteen years away from home 
and perhaps tired of an existence more than a little Bohemian, was feeling 
domestically inclined. Anne-Toinette Champion her name sometimes ap 
pears as Anne-Antoinette did much more for Diderot than she is usually 
given credit for. Not least of these benefits was the fact that her being hard 
to win drew Diderot away from that inclination toward dissoluteness and 
debauchery that was quite evidently a part of his bachelor existence. 7 Those 
shirts played a great role; how great may be detected in the implications of 
a remark that Diderot happened to toss off in casual conversation many 
years later. I have heard Diderot say, wrote Nicolas de Chamfort, an 
anecdotist of some repute in his century, that a sensible man of letters might 
be the lover of a woman who writes a book, but he ought to be the husband 
of her only who knows how to sew a shirt. 8 This remark of Diderot has in 
it unpremeditated sadness and poignancy because it sums up so accurately 
the history of his own marriage. 

Nevertheless, they [the Champions] unceasingly referred to his entry 


into the Seminary/ continues Mme de Vandeul, but, having perceived more 
than once that he was pleasing to my mother, he confessed to her that he 
had hit upon this fib only for the purpose of being allowed in her home, and 
assured her with all the violence of his passion and of his character that he 
was determined not to take orders but, on the contrary, to marry her. My 
mother made only such objections as reason might suggest; in view of their 
mutual affection, these objections had little weight. My grandmother declared 
it to be most contrary to reason to marry oneself to such a hot-head, to a 
man who did nothing, and whose whole merit, she said, was in having a 
golden tongue with which he turned her daughter s head; but this mother, 
who preached so sensibly, was herself fond of my father to the point of 
distraction. . . . Finally they all decided that my father should visit Langres 
and that he should come back fortified with his family papers and the con 
sent of his parents/ 9 

Meanwhile, even before Diderot left for Langres, the idea of his be 
coming a lawyer had been revived. This we learn from an undated letter 
he wrote to Anne-Toinette: 1 have just received a letter from the papa. 
After a sermon two ells longer than usual, plenary liberty to do anything 
I want, provided I do something. Do I persist in the resolution of going 
into a solicitor s office? Order given to seek out a good one and pay down 
the first quarter right off. . . . 10 It is interesting that this project of be 
coming a solicitor crops up a second time in Diderot s life. Perhaps we may 
conclude that not long previously Diderot had informed his family that 
he had decided not to enter Saint-Sulpice on i January 1742. But did Diderot 
actually again start work in a solicitor s office? Other letters to his fiancee 
give absolutely no indication one way or the other. Naigeon implies that 
he did, by saying that Diderot fell in love sometime before entering the 
solicitor s office, and Naigeon, though tiresome, is an authority who may 
not with impunity be ignored. 11 

From these letters to his fiancee it can be deduced that Diderot left Paris 
for Langres on 7 December I742. 12 He found his parents much concerned 
about his future, but also much impressed when galley proofs arrived of 
the translation he was doing from the English of Temple Stanyan s Grecian 
History: My dear sweetheart, these proofs of my book, sent to me thrice a 
week, are doing wonders. My father and mother, who didn t seem too much 
inclined to let me go back, are going presently to be the first to hasten my 
return, so convinced are they that I am occupied up there with something 
useful. . . . 13 Moreover, Diderot found that the decision that my younger 
brother has just taken has put the finishing touch to deciding my father to 


leave me my freedom. " This freedom may refer to Diderot s previously 
stated intentions of becoming an ecclesiastic. Just at this time his younger 
brother had entered the seminary to become a priest, and it may be that 
the Diderot parents did not desire both their sons to adopt a calling that 
precluded their having legitimate children" This did not mean however, 
as Diderot soon found out, that the family was willing to accept any daughter- 
in-law he might propose for them. 

At first the Langres visit went well: no doubt Diderot s tactful gift of 
a book of piety for his father, an Office of the Dead, was well received. 1 It 
was probably during this visit, too, that Diderot went to see his sister who 
had become a nun, a visit mentioned by Mme de Vandeul, but m a context 
that is very vague. 17 It may be that during this comparatively lengthy visit 
Diderot let slip some views on religion that made his mother fear for his 
orthodoxy, for Diderot s father, writing some years later, makes an allusion 
to the remonstrances that she made to you by word of mouth. 18 Since this 
visit to Langres is the only one known to have been made by Diderot be 
tween his first going to Paris and his mother s death in 1748, this testimony 
provides useful evidence in dating the progression of his heterodox ideas, 
although it should be admitted that it probably took very little to alarm the 
simple faith of his unsophisticated and pious mother. 

Diderot s strategy was to persuade his parents to fix an annuity upon him. 
Following that, he intended to broach the subject of his intended marriage. 
But by this time Anne-Toinette s letters, addressed to him in care of one 
of his cousins named Humblot, were reaching him, and one of these epistles, 
full of injustices and cutting words and evidently accusing him of being 
too dilatory, caused him to force the pace. 19 A later letter from Diderot 
mentioned that thy impatience, which I can only praise, since it is a proof 
of thy love, has just hastened my declaration/ 20 This declaration was so 
poorly received that Diderot appears to have demanded, in a fit of passion, 
that he receive his share of the family inheritance out of hand, failing which 
he actually threatened to have his father arrested. It must have been a 
tempestuous scene. The fine plans of Diderot the son were quite undone and 
Diderot the father took steps of his own. On i February 1743, he wrote to 
Mme Champion: If your daughter is as well born and loves him as much 
as he believes she will exhort him to renounce her hand. It is only at this 
price that he will recover his liberty, because, with the aid of friends of mine 
who have been made indignant by his impudence, I have had him put in 
a safe place, and we have, I am sure, more than enough backing to keep 
him there until he changes his mind. 21 


Parental authority went rather far in the ancien regime, and it was not at 
all uncommon for heads of families to call to their assistance the supreme 
authority of the king in cases of particularly stubborn resistance. If passions 
were too hot, they were cooled off by the simple device of arrest and in 
definite detention in some monastery, castle, or prison. Thus the power of 
the state operated to moderate the passions of junior members of a family 
while abetting those of the head of it. Unfaithful wives, daughters eager to 
elope, sons desirous of marrying beneath them could be made unwilling 
guests of the king for prolonged periods during which it was hoped that 
leisured meditation would temper the promptings of impetuous desire. The 
most famous example in the eighteenth century of arbitrary arrests and im 
prisonments used to enforce family discipline was that of the turbulent 
Mirabeau family. At one time the Marquis de Mirabeau had every single 
member of his family, save himself and one other, under lock and key. 22 This 
was operating on a grand scale, and the Diderots, of course, were not so 
magnificent. But it is quite evident that Diderot s father intended to utilize 
the power of the state indefinitely until his son should change his mind. 

It is extremely interesting to learn that Diderot was put under coercive 
detention. It is no less so to know that he escaped it. After having experienced 
unheard-of torments [he wrote to Anne-Toinette], here I am at liberty. 
Shall I tell you? my father carried his harshness to the point of having me 
shut up with some monks who have employed against me all that the most 
determined maliciousness could imagine. I flung myself from the window 
the night of Sunday going on to Monday. ... I have come thirty leagues 
on foot in detestable weather. ... If you resent the lack of success of my 
journey and if you should show that you do, I am so overwhelmed with 
afflictions, I have suffered so much, so many trials still await me, that my 
decision is taken, I shall finish everything at one stroke; my life or death 
depends upon the welcome you give me. My father is in such a fury that I 
do not doubt at all that he will disinherit me, as he has threatened. If I 
lose you, too, what remains to me that can keep me in this world ? 

1 shall not be in safety at all in my former apartment, for I have no doubt 
that Brother Angel has already received orders to have me arrested, orders 
which he would be only too glad to carry out. Do me the favor then of 
finding me a furnished room near you or somewhere else. . . . 

[P. S.] I forgot to mention that to prevent my running away, they took 
the useless precaution of cutting off half my hair. 

In the whole family, I had on my side nobody but one aunt. I went to 
stay with her during our quarrels. 2S 


On his return to Paris Diderot apparently went underground for a con 
siderable period. Perhaps the only wonder is that the police made no 
determined effort to catch up with him, for, after all, he had flouted the 
royal authority. This was an example, one is tempted to think, of how a 
revolution could incubate in France, for the authority of the state repeatedly 
showed itself arbitrary and irritating without being resolutely and effectively 
repressive. During this year of lying low, Diderot occupied lodgings in the 
Rue des Deux-Ponts on the old lie Saint-Louis, that islet in the Seine which 
even today preserves an air of detachment, as though living untouched by 

. i 04 

time m an age gone by. 

The family tradition, as reported by Mme de Vandeul, was that Anne- 
Toinette Champion intended to see no more of her lover: She assured my 
father very explicitly that she would never enter a family where she was 
not regarded favorably; she asked him to go away, and in spite of his impor 
tunities ceased to receive him. But Diderot became ill, according to this 
family story: *My mother could not remain at peace and know that he was 
suffering. She sent a friend to get news of him. She was told that his room 
was a regular kennel, that he was without hot food or any care, and was 
emaciated and melancholy. She thereupon made up her mind, went to see 
him, promised to marry him, and both mother and daughter became his 
nurses. As soon as he could go out, writes Mme de Vandeul, they were 
married. 25 

It is noteworthy that the marriage, which occurred on 6 November 1743, 
was not solemnized until the groom had passed his thirtieth birthday. This 
was probably intentional, for by a royal ordinance of 1697 it had been estab 
lished that a son who married without his father s consent before the age 
of thirty could be disinherited. 26 As for the customary marriage settlement, 
Diderot later wrote: My wife s relatives had our contract drawn up and I 
signed it without reading it. The reason was that I loved her. 27 Concerning 
this marriage, the most copious source of information is provided by Jal, 
an indefatigable and reliable antiquarian: Diderot . . . had one ban pub 
lished at the church of Saint-Louis [-en-l lle, his parish church], and at the 
church of Saint-Severin [Anne-Toinette s parish church], paid for dispensing 
with the two others, and presented himself before the parish priest of Saint- 
Severin for permission to be betrothed and married on the same day in the 
church of Saint-Pierre-aux-Boeufs. Saint-Pierre shared with the Cardinal 
Le Moine and some of the small parishes of the city the privilege of solem 
nizing marriages that were quasi-clandestine. People went there to have 
marriages consecrated against which there were family repugnances or some 


scandal or other. Without display, without carriages, without guests, the 
people to be married presented themselves at an early hour at the sacristy, 
asked for a low mass, signed the marriage certificate witnessed by four 
persons, and left the church without bustle or pomp, just as they had arrived 
there. "Denis Diderot, a burgher of Paris, a son of full age of Didier 
Diderot, master cutler, and Angelique Vigneron," and "Anne-Toinette 
Champion, residing at Rue Poupee, in the parish of Saint-Severin," pre 
sented themselves on 6 November, 1743 the cold favoring the incognito 
that they wished to preserve at Saint-Pierre-aux-Boeufs, and were united 
in the presence of "Marie Maleville, residing at Rue Saint-Severin," of 
"Jacques Bosson, vicar of Saint-Pierre-aux-Boeufs, of Jean-Baptiste Guillot, 
former canon of Dole, and of a neighbor of the bride." 28 Saint-Pierre-aux- 
Boeufs was located on the lie de la Cite, just a stone s throw from Notre- 
Dame, on a site now occupied by the Hotel-Dieu. Mme de Vandeul says 
that the marriage took place at midnight. 29 

Diderot s letters from this period of courtship and engagement trace the 
familiar progress of a lover from the formal vous to the intimate tu, and 
then when lovers quarreled the regress back to vous again. Here are 
the endearing nicknames, with a special tinge of Diderot s exuberance on 
them: Ninot writing to his Nanette/ his Tonton. And the letters reveal, 
too, much of the character and temperament of the bride and groom. They 
allow us to perceive Anne-Toinette s hardheadedness, her evident ability 
to be coolly skeptical and disconcertingly realistic. These were congenital 
qualities, no doubt, but also ones confirmed by the narrowness of a neces 
sitous existence and reinforced by the conviction that life is hard. They were 
qualities that always grated on that exuberance of his, on his easy en 
thusiasms, on that half of him that loved to gamble, to buy expensive prints, 
to be late to appointments, to forget what day of the week it was, and to 
ignore the fact that a cab he had ordered was standing outside running up 
a bill. So Diderot expostulates with her, as on 2 January 1743 : You know my 
sensitivity. Judge, then, of the state you have put me into. You will be my 
cruelest enemy if you do not hasten to redress the wrong you have done to 
him who in the whole world merits it the least and loves you the most. 30 And 
in the last letter extant from the period before their marriage, a letter which 
shows that Anne-Toinette came very close to breaking off the marriage 
entirely, Diderot complains of the hardheartedness of your way of doing 
things. 31 

These letters also show us in the early Diderot a Diderot already striking 
some of his most characteristic poses the plausible and persuasive Diderot 


of the golden tongue, facilely making assurances of eternal devotion; the 
disarmingly candid Diderot, blandly confessing the extent of his previous 
vagaries in order to show how greatly he had reformed: The fire that 
consumes a young libertine (for I have truly merited the name) for his 
neighbor s wife is a fire of straw which soon dies down forever; but that 
which consumes a virtuous man (for I merit this name since you have made 
me well-behaved) for his own wife never goes out. Alas! this was not only 
an erroneous prophecy; it was fustian. Anne-Toinette, however, married 
him in spite of it, perhaps because of it. And finally, there is revealed in 
these letters the complacent Diderot, naively complimenting himself, as 
he so frequently did, concerning his own virtue: . . . my gratitude, my 
probity, for I pride myself upon having as much of it as any one alive; 
the tears that I shed when I was on the point of losing you, my oaths of 
fidelity, thy love, thy qualities of body, heart, and mind, all ought to assure 
you of an eternal reciprocation on my part. 32 

For the next year and more, documentary evidence concerning the newly 
married couple is exceedingly meager. On 13 August 1744 those who 
like to count will notice that it was a few days more than nine months after 
their marriage their daughter Angelique was born, and was baptized the 
next day at the church of their parish, Saint-Nicolas-du-Chardonnet. 3a At 
this time the Diderots were living in the Rue Saint-Victor, a twelfth-century 
street, part of which is still in existence and in which was located the 
Seminary of Saint-Nicolas, that seminary which Diderot had once told the 
Champions that he intended to enter. But between the birth and the death 
of little Angelique, the Diderots evidently moved. When their six-weeks-old 
daughter was buried on 29 September at the parish church of Sainte- 
Marguerite-de-Paris, their address was given as Rue Traversiere, then a 
street in the suburbs, almost in the open fields, out beyond the Bastille. 34 
It is astonishing, too, that the parish burial register describes Diderot as a 
day-laborer. Perhaps to conceal himself from his relatives or the police, Diderot 
had moved to this out-of-the-way suburb. There must have been some power 
ful motive operating to induce him to move from the Left Bank, for almost 
all his long career in Paris was spent in that part of the city. Diderot did 
indeed possess the Latin Quarter sort of temperament, and the rive gauche 
should be proud of so representative a son. 

Diderot s wife lived an extremely retired life, partly because they were 
impecunious, partly because her husband was jealous, partly because they 
kept their marriage a secret from the relatives at Langres. So well, indeed, was 
the secret kept that it was not before 1749, six years after the marriage, that 


old Didier Diderot heard a rumor that his son was married and the father 
of children. 35 Moreover, during at least the first four years of their mar 
riage, the Diderots attempted to conceal the fact of that ceremony by having 
Mme Diderot live under her maiden name. 36 From her point of view, con 
vent-nurtured as she was, it must have been a real sacrifice to have people 
suppose her children illegitimate. For Diderot, the inevitable result was that 
he spent a good deal of his time acting like a bachelor, with the unfortunate 
consequence that he became entirely habituated to that situation. When 
conditions changed later, he did not change with them, but continued to 
go his own way, never dreaming of allowing his wife to share any part of 
his social or intellectual life. Unconsciously he took advantage of her willing 
self-sacrifice: My father was of too jealous a disposition to allow my mother 
to continue a business that would require her to receive and deal with 
strangers/ wrote his daughter. He exhorted her to give up this business. She 
experienced great difficulty in consenting to do so: destitution did not 
frighten her as far as she herself was concerned; but her mother was aged, 
she was faced with the possibility of losing her, and the thought of not 
being in a position to provide for all her mother s needs tortured her. Never 
theless, as she persuaded herself that this sacrifice would make her husband 
happy, she made it. A charwoman came each day to sweep the small apart 
ment and bring the day s provisions. My mother provided for all the rest. 
Often, when my father was eating out, she dined or supped on bread, and 
took great pleasure in thinking how on the morrow she would be able 
to make her customary meal for him twice as good. Coffee was too con 
siderable a luxury for this sort of household; but she did not want him to be 
deprived of it, and every day she gave him six sous that he might go take 
his cup at the Cafe de la Regence and watch them play chess/ 37 

These days of courtship and early marriage saw also the cementing of 
one of the famous friendships of the eighteenth century, that between Diderot 
and Jean-Jacques Rousseau. Rousseau s early life is so well known, and is 
so well told in his Confessions, that no mention of it needs to be made 
here, save to say that in August 1742 he had arrived in Paris with a new 
scheme of musical notation that he had devised. A Swiss named Daniel 
Roguin introduced him to Diderot, and there immediately grew up an 
intimate friendship, based initially on the interest they shared in matters 
musical. 38 

Temperamentally these two young men were very different, congenial 
though they were in the first ten years of their friendship. The fact that in their 
frequent games of chess Rousseau invariably won is itself an indication of 


their differing personalities and temperaments. 39 Diderot was big-hearted, 
well meaning, rather grandly negligent, brash, and tactless. Although he 
deemed himself shy, he was in reality endowed with an over-brimming 
measure of self-confidence, which Rousseau, to an unusual degree, both 
lacked and admired. Rousseau, shy, tortured by feelings of inferiority, now 
and then convulsively assertive, desirous of being led while living in jealous 
dread that he might be, was just as brooding and paradoxical a person 
then as he was in the later years when he became famous. 

In July 1743, Rousseau left Paris for Venice, where he had an appointment 
as secretary to the French embassy. Fifteen months later he was back in 
Paris, having quarreled with his ambassador, and it was there, in March 
of 1745, that he became interested in Therese Levasseur, a servant girl at 
the hotel at which he was staying, and presently began to live with her. 40 
He of course knew of Diderot s attachment and speaks of Anne-Toinette 
in unflattering terms: He had a Nanette just as I had a Therese; that con 
stituted between us one conformity the more. But the difference was that 
my Therese, as good-looking as his Nanette, had a gentle disposition and 
an amiable character, suitable for attracting a virtuous man; while his 
[Nanette], a shrew and a fishwife, showed nothing to other people that 
could make up for her bad education. 41 

In 1812, Anne-Toinette s daughter, herself fifty-nine years old in that 
year, commented explosively upon these lines, in a spectacular display of 
filial spirit. Yet she made admissions regarding her mother s difficult temper. 
Where my father was in error was in not forming her for the world, 
because, born jealous, he did not wish that she should see it. ... Solitude, 
domestic cares arising from a very restricted income, the chagrin caused 
by the love affairs of my father, her ignorance of the manners of polite 
society, had soured her temper; and to scold became a habit. . 42 

Diderot s marital difficulties were to a large degree his own fault and arose 
from the fact that he got into the habit of treating his wife as though she were 
a concubine. 


First Fruits 

D 1 

DIDEROT at the age of thirty was a necessitous young 
man without either reputation or livelihood. His 
recent quarrel with his family had cut him off from any paternal support, 
yet he was too independent in spirit to tie himself to a profession or undergo 
the constraint of being a tutor or take up the daily routine of some occupation 
in trade or commerce. He had described himself truly to his friend Wille 
as a person striving to become a philosopher and a man of letters; he was 
as yet a complete unknown. Certainly his career was not going to be dis 
tinguished by traits of unusual precocity, that was already evident; yet he 
yearned to find glory as well as truth, if we may take as being partly auto 
biographical his picture of the ambitious child whom the sensible father 
tries to restrain from leaving home: Wretched child, what are you going 
to do ? You are not sure to attain glory, and you rush headlong into poverty. x 

The tenor of his life during these difficult years suggests that his principal 
objectives were intellectual freedom, the attainment of glory, 5 the mainte 
nance of personal independence, and survival! But to achieve all these 
things, in proper and desired combination, was not easy. Moreover, Diderot 
had compounded the risks of his precarious existence by assuming the added 
responsibilities of a wife and, presently, a child. Had Diderot been less 
jealous, he might have allowed his wife to continue meeting the public in 
the small lace and linen trade in which she had earned her livelihood before 
marriage. Had he been less proud, he might have sought the patronage of 
the great. It was like Diderot to do neither. 

The price paid for this independence was insecurity and impecuniosity. 
The easy and traditional way would have been to find a rich man to whom 
to inscribe flowery letters of dedication. But just in these very years literary 
men of spirit were discovering that it was possible to live a life of inde 
pendence, even though its cost was high. This is the purport of D Alembert s 



Essay on the Intercourse of Men of Letters with the Great (1753) and Dr. 
Johnson s famous letter to Lord Chesterfield (1755). Yet it was hazardous 
and far from easy, even for men of talent and courage, to be independent 
and still avoid hunger. Even the proud and sensitive Jean-Jacques Rousseau 
was fain to be a secretary to the condescending Mme Dupin. Diderot refused 
to be patronized. He sought contractual relations, not feudal ones. No 
doubt his publishers exploited him, as he and his friends were wont to 
complain, but at least he avoided dependence upon the haughty and uncer 
tain largess of a patron. 

Such an attitude led him into an existence of what would now be called 
free-lancing and free-lancing at its hazardous and vicissitudinous worst. 
Probably he received some payment for writing several reviews in a periodical 
entitled Observations sur ks Ecrits Modernes. This journalistic enterprise, 
which was published for eight and a half years beginning i March 1735, 
was edited by the Abbe Pierre-Frangois-Guyot Desfontaines, a man of some 
literary ability who is remembered for little save that he had the misfortune 
or bad judgment to fall foul of Voltaire. In a statement made to the Lieu 
tenant-General of Police in 1749, Diderot declared that several of the articles 
in the Observations were of my making. 2 These contributions were pub 
lished anonymously, however, and it is impossible now to identify Diderot s 
work in these superannuated pages. 

Desfontaines, a competent critic, encouraged Diderot in another branch 
of letters, although the advice bore no immediate fruit. It is the Abbe dc 
La Porte, writing for his newspaper, L Observateur Litttraire, in 1758, who 
tells us of the incident. 1 recall what was said to me one day by the celebrated 
Abbe Desfontaines to whom M. Diderot, then still very young, had pre 
sented a dialogue in verse, "This young man," he said to me, "is studying 
mathematics, and I have no doubt that he is making great progress, for he 
has a great deal of ability; but from the reading of a play done in verse 
that he brought to me some time ago, I counseled him to give up these 
serious studies, and devote himself to the theater, for which I believe him 
to have a real talent." 3 This advice would have had to be given before 
1745, since Desfontaines died in that year. 

In 1742 Diderot had for the first time the satisfaction of seeing his name 
in print. His satisfaction may have been alloyed with some vexation, however, 
for the printer had garbled his name. Over the name of P. D. Diderot there 
appeared an epistle in verse to a Monsieur B * * *, probably Baculard 
d Arnaud (1718-1805), a very second-rate man of letters. This bit of verse 
appeared in Le Perroquet, a collection now as rare as it was then obscure, 


published at Frankfurt am Main. 4 A flavorsome touch of the archaic is 
all that distinguishes these competent but rather commonplace lines, which 
bespeak an author rather more practiced than inspired. Throughout his life 
Diderot was to turn now and then to this form of expression, being able to 
produce well-polished occasional verse almost on demand. Some reflections 
caused by a cold sore, lines written on the back of a letter to Anne-Toinette, 
and the epistle in Le Perroquet are the earliest known examples of his 
occasional impulses to versify. 5 

It was not as an author, however, but as a translator from the English 
that Diderot managed to support himself for a number of years. When and 
why he learned the language is a matter of conjecture; certainly he had 
done so by 1742, for he was then translating the work on Greece. Perhaps 
his reason for learning it was the curiosity excited by a book like Voltaire s 
Letters concerning the English Nation, the French edition of which (1734) 
had introduced into France the ideas of Locke and Newton, as well as 
British notions of liberty and religious toleration. How he learned the 
language he tells us himself, by recalling that he passed it through the Latin. 6 
This suggests that he taught himself, a supposition the more likely since 
he appears to have been unable to write English or to speak it, the draft of 
a letter composed in English late in his life being the sole evidence to 
the contrary. 7 Still, his ability to read English was an unusual accomplish 
ment in eighteenth-century France, enabling him to go to the fountainheads 
of English science, literature, and philosophy, and to read English authors 
who, unlike Bacon and Newton, wrote only in the vernacular. 

This was an inestimable advantage for an eighteenth-century Continental 
thinker. English influences the writings of a host of deistic authors like 
Toland and Clarke and Wollaston, arguing for natural religion; the sci 
entific ideas of Bacon, Boyle, and, most important, Newton; the psychological 
ideas of Locke, emphasizing that all we can ever really know is transmitted 
to us by one of our five senses had an exciting and unsettling effect upon 
conventional ideas, especially upon conventional ideas in France. No doubt 
it all started innocently enough in the hope that by using the scientific 
method preached by Bacon and the rational methods used by Newton, men 
would be vouchsafed the privilege of peering a little deeper into the nature 
of things. But what happened was that the scientific and rational implica 
tions of English ideas greatly affected the metaphysical and theological think 
ing of the time. Moreover, the doctrines of the English writers and scientists, 
when transplanted to France, took on an exaggerated and revolutionary 
character that they did not have at home. Probably the reason was that 


Catholic orthodoxy was more absolutist and had less give than the orthodoxy 
of a Protestant country. At all events, English ideas were the most excmng 
ones of the eighteenth century, and English thoughts m French heads 
produced in the long run some astonishing and explosive consequences. 
Diderot, with his mind and temperament, would natural y have played a 
leading part in this exciting and dangerous decanting of ideas. But add 
to this the fact that he was able, unlike many others of his cotene, to grapple 
with these ideas in the original, and had done so in a number of h early 
literary chores, and a solid basis is established for his ability to assert and 
make good his intellectual leadership. 

The earliest of Diderot s translations from the English was Temple 
Stanyan s Grecian History, the first complete edition of which had appeared 
in 1730. The Dictionary of National Biography speaks of Stanyan as an 
excellent scholar and of his history as a compilation which held the field 
until the appearance of the much larger history by William Mitford almost 
fifty years later. As we have already seen, the galley proofs of Diderot s 
translation created a sensation upon their arrival in Langres. The work, 
entitled Histoire de Greece, appeared in three volumes in i 743 . 8 The fort 
nightly Journal des Sqavans, the blue-ribbon periodical of that era, did the 
history the honor of quoting it copiously in three installments, but of the 
translator s work it finally remarked, disappointingly, that it was written 
rather negligently. 9 A Berlin review of Diderot s translation, written m 
1773 and no doubt inspired by the malevolence of Frederick the Great, 
spoke of it superciliously as a long task during which the creative spirit 
of M. Diderot took a rest. 10 Maybe so; but if one be content to ask no more 
of a translation than that it be accurate and faithful, a comparison of the 
original and of the French version shows that Diderot was a quite skillful 
translator. For the Stanyan work Diderot received the sum of three hundred 

francs. 11 

Diderot s next exercise in rendering from the English was more a para 
phrase than a translation. Yet it is a very important work, indeed, for under 
standing the growth and development of his thought. The book in question 
was Lord Shaftesbury s An Inquiry concerning Virtue and Merit, which 
appeared in its French dress in 1745, purportedly published in Amsterdam 
under the title Principes de la philosophic morale; ou Essai de M. S * * * 
sur le merits et la vertu. Avec reflexions. It was Diderot who furnished the 
reflections in a preliminary discourse and lengthy footnotes to which stu 
dents of Diderot now turn for precious indications of the unfolding of his 
ideas. 12 Since this book was published in 1745 Diderot s presentation copy 


to Rousseau is dated 16 March 1745 it is to be presumed that Diderot 
was engaged upon the work in the months following his marriage. 13 

It will be noticed that the French version is anonymous: neither Shaftes- 
bury s name nor that of his translator was mentioned. The reason was that 
there was some danger involved in presenting to the French public a work 
that declared so boldly for the existence of a natural morality independent 
of the sanctions of any particular religion or church. Shaftesbury very much 
believed in God, but his religion and morality were such as are revealed 
more by reason than by Scripture. Happily, the French press reviewed the 
book quite favorably and without too much emotion. The Jesuit Journal de 
Trevoux, a very influential magazine edited at Paris and (since 1734) printed 
there, ran its review of the book as its leading article for the issue of February 
1746. Imagine Locke s discoursing on morality/ it said. Thus the author 
appears to us, and, if one wishes, so does the Translator or Compiler of this 
volume. 14 But the Journal des S$avans, while favorable, had some mental 
reservations: If he [the author] conducts the human creature, as he says, to 
the doors of our temples, he seems at the same time to be wishing to excuse 
him from entering them. 15 

A comparison of the translation with the original shows that Diderot was 
quite successful in wrestling with the convolutions of Lord Shaftesbury s 
syntax, which still remained seventeenth-century even though he wrote in the 
Age of Addison. 16 Whatever Diderot gained in clarity, however, he probably 
lost in savor. 17 This was, of course, the fate of almost all English authors 
in eighteenth-century French translations, Shakespeare most of all. Never 
theless, Diderot was quite faithful to his task more, even, than he claims 
to be, for he wrote in his preliminary discourse, I have read and reread him; 
I have filled myself with his thoughts; and then I closed his book, so to 
speak, when I took up my pen. 18 Still, there is a great deal of the char 
acteristic Diderot in this little treatise: the mischievous and pointed placing 
of footnotes where Shaftesbury s implicit heterodoxy was most apparent; the 
lengthy quotation from skeptical authors like Montaigne or extremely pagan 
ancients like Petronius; the use of concepts, that, like leitmotives, occur in 
Diderot s later writings, such as the notion that human beings are like 
musical instruments of which our passions are the strings; 19 the extremely 
personal approach to the reader, even in works of philosophy, as in his re 
mark, I have passions, and I would be sorry not to have them: I love very 
passionately my God, my king, my country, my parents, my mistress, and 
myself. 20 Moreover, in these notes he indulged his inveterate fondness for 
flushing more ideas than he could bag, a failing that was alluded to by the 


reviewer in Desfontaine s Jugcmens sur Qudqucs Outrages Nouveaux, who 
named Diderot right out and evidently knew him. Let me be permitted to 
say to him, following Doctor Swift, in whom he frequently takes refuge, 
that digressions in a book are like foreign troops in a state, making one 
suspect that the natives lack vigor and courage. 

Most characteristic of all in the Essai sur k merits et la vertu is Diderot s 
appeal for religious tolerance, which was quite in the spirit of Shaftesbury, 
too. In the dedicatory epistle To my Brother/ Diderot wrote, But if you 
will recall the history of our civil troubles, you will see half the nation 
bathe itself, out of piety, in the blood of the other half, and violate the 
fundamental feelings of humanity in order to sustain the cause of God; 
as though it were necessary to cease to be a man in order to prove oneself 

religious! 122 

There is much in Shaftesbury s thought that made a profound and per 
manent impression on Diderot, who shows in his footnotes to this essay 
his familiarity with all of Shaftesbury s works. 23 He liked Shaftesbury s doc 
trine that man is endowed by nature with a moral sense; that man s emotions 
and passions can work for good and not exclusively for evil, as the older 
generation of philosophers and Christian moralists had held; 24 that it is 
possible to build a morality based on reason; and that there is an extremely 
close relationship, practically an identity, among the good, the beautiful, and 
the true 26 Many, moreover, of the anticlerical or anti-Christian facets of 
Shaftesbury s thought are directly reflected in Diderot s later work, for ex 
ample, his influential Philosophical Thoughts. 

Diderot s dedication of his work on Shaftesbury, To my Brother,* was 
perhaps only figurative. Didier Diderot, then studying theology in Paris 
and approaching his ordination to the priesthood, can scarcely have welcomed 
the dedication of such a volume even though published anonymously. There 
is no record of his protesting against the dedication, nor indeed of any 
intercourse between the two brothers during their joint residence in the 
capital. 27 For some reason, however, the second edition found aunt sub 
stituted for brother* in the dedicatory passage. 

Diderot s next adventure in translation was a considerable one, but 
accomplished without reflections.* Briasson, the same bookseller who had 
brought out the Stanyan Histoire de Grece, undertook to publish Robert 
James s medical dictionary, a work which had appeared in three folio volumes 
in London between 1743 and 1745. The scope of the work, which may very 
well have given Diderot ideas of how to lay out an undertaking of encyclo 
pedic character, is worth indicating by quoting its title in all its eighteenth- 


century lengthiness: A Medicinal Dictionary; including Physic, Surgery, 
Anatomy, Chymistry, and Botany, in all their Branches relative to Medicine. 
Together with a History of Drugs; and an introductory Preface, tracing the 
Progress of Physic, and explaining the Theories which have principally 
prevail d in all Ages of the World. By R. James, M. D. These ponderous 
folios (Volume I weighs eleven pounds, fourteen ounces), called by Mark 
Twain A Majestic Literary Fossil/ were illustrated by sixty-three quite 
good copper plates of surgical instruments and operations, so that the whole 
work with its broad approach, its sense of the interrelationship of the sci 
ences, its engravings, and its cross references was of a nature to kindle in 
a person as imaginative as Diderot a lively conception of what a similar 
work could do for the whole sweep of human knowledge. 28 That there is 
so close a connection between the Medicinal Dictionary and the Encyclopedic 
is conjectural but nevertheless chronologically possible. And inasmuch as 
Diderot, by his own account, worked almost three years on the project, he 
must have learned a great deal about putting a work of considerable mag 
nitude through the press. 29 Moreover, it is highly probable that Diderot s 
deep and abiding interest in physiology, anatomy, and medicine was estab 
lished as a result of the extensive task of translating Dr. James. Briasson 
brought the work out in six folio volumes between 1746 and 1748 under the 
title Dictionnaire universel de medecine, etc., translated from the English 
of Mr. James by Messrs. Diderot, Eidous and Toussaint, 5 30 It is of interest 
to learn that Samuel Johnson, a close personal friend of Dr. James, con 
tributed to the Medicinal Dictionary its dedication, its prospectus, and some 
of its articles, so that Diderot probably translated some of Dr. Johnson s 
august prose. 81 

Diderot was an extremely generous man though distinctly more gen 
erous of his time than of his money and the work of translating the 
Medicinal Dictionary became the occasion for a remarkable display of this 
quality. He had just undertaken this business when chance brought him 
two men the one Toussaint, author of a little work called Les Moeurs, 
the other an unknown but both of them without bread and seeking work, 
wrote his daughter. My father, having nothing, deprived himself of two- 
thirds of the money that he could count upon from this translation, and 
engaged them to share with him this little undertaking. 32 

Mme de Vandeul speaks here with a note of unjustified condescension 
about Francois-Vincent Toussaint and his famous book Les Moeurs, pub 
lished in 1748 and condemned on 6 May of that year by the Parlement of 
Paris. 33 Les Moeurs was one of the first (and therefore one of the boldest) 


works in the eighteenth century to set forth the arguments for a natural 
morality unbolstered by any religious belief or public cult. No doubt Tous- 
saint was inspired and abetted in this daring enterprise, both as to the 
intellectual content of the essay and the publication of it, by the example of 
Diderot, whose Penstes philosofhiques had appeared two years previously. 
A police report on Toussaint, under date of i April 1749, spoke of him as 
being closely associated with Diderot and D Alembert and working with 
them on the Encyclopedic?* It is true that he contributed some articles on 
jurisprudence to Volumes I and II of the Encyclopedic, but thereafter he 
had no connection with it; we do not know why. 

The unknown mentioned by Mme de Vandeul was the Eidous (Marc- 
Antoine by given name) who appears on the title page of James s Dictionnaire. 
Eidous had been an engineer in the Spanish army before coming to Paris, 
where he eked out a long life by doing translations from the English by 
the yard/ as Grimm contemptuously described it. 35 Thus in the fullness of 
time Eidous became the translator (1767) of Horace Walpole s The Castle 
of Otranto?* Eidous existed on the periphery of literature, never translating 
very well Grimm said he rendered the English into a language all his 
own: the Eidoussian language 37 never venturing to embark by himself 
on the deep waters of original composition. It was he who was to contribute 
to chapter XLVII of Diderot s novel Lcs Bijoux indiscrets, a chapter describ 
ing the adventures of what Ernest Hemingway would call *a big, inter 
national whore. Some of Eidous passages in English and Italian certainly 
do rival Aretino, as a secret police report of the time said of them, 38 and 
probably come close to surpassing in pornography anything else that has 
appeared in print. Diderot s association with this elevating companion ap 
pears not to have extended beyond these early years. Eidous did a few unim 
portant articles for the Encyclopedic and thereafter fades out of focus in 
the Diderotian kaleidoscope. 

During this early period certainly before 1749 Diderot wrote some 
notes and comments on a French translation of Pope s Essay on Man?* This 
may have been intended to be nothing more than an exercise to improve his 
powers of rendering from the English, but it may also have had some lasting 
effect upon his thought. Certainly Virtue alone is happiness below, 1 comes 
close to expressing Diderot s whole philosophy of living. 

Sometime between September of 1744, when they had buried their first-born 
child in the churchyard of Sainte-Marguerite-de-Paris, and May of 1746, when 
their second baby was baptized, the Diderots changed their residence back 
to the Left Bank, The baptism of Francois-Jacques-Denis Diderot accordingly 


took place in Saint-Medard, the parish church of the street in which they 
then resided. The churchyard of Saint-Medard had been from 1728 to 1732 
the scene of some healings, alleged to be miraculous, that took place over 
the tomb of a Deacon Paris. This man had been a Jansenist, and his fellow 
sectaries, delighted to discover among themselves a saint (for the Jansenists 
did not have many), lost no opportunity to publicize his thaumaturgical 
powers. The result was that enormous crowds visited the place, creating 
a frightening crescendo of religious frenzy and hysteria. This was the period 
of the convulsionnaires. The government, as unsympathetic to Jansenist mir 
acles as to Jansenists, closed the cemetery, causing some unknown wit to 
place a placard on the gates: By order of the King, God is forbidden to 
work miracles here. The excitement slowly subsided, but it left the phi 
losophers of the century shuddering, for to them it seemed to prove the 
ugliness of religious fanaticism, as well as to reveal that the Jansenists were 
quite as far gone in obscurantism as any of their antagonists. 40 

Saint-Medard, then, of unsavory memory to a person like Diderot, who 
alludes to the convulsionnaires in several of his Philosophical Thoughts, 
had now become the church of his parish. In the baptismal certificate the 
Diderots were mentioned as living in the Rue Mouffetard. This street, long, 
populous, odorous, and poverty stricken, probably looks very much now as 
it did then, and still offers to the tourist or photographer some of the oldest 
roofs, the oddest angles, and the most captivating juxtaposition of planes in 
all of Paris. 

While the Medicinal Dictionary was still in the process of being trans 
lated, Diderot wrote a little book that ought to be considered, in view of 
the reverberations it caused and the polemics it aroused, one of the most 
important of the eighteenth century. This was the Pensees philosophiques, 
bought by the book publisher Durand, who was to be one of the partners 
in publishing the Encyclopedic; printed surreptitiously in 1746 by a man 
named L Epine; and then sold clandestinely by various bootlegging tech 
niques in which the eighteenth century was becoming remarkably pro 
ficient. 41 So incisive and effective was this little book that it came under the 
disapproving scrutiny of the Parlement of Paris. That court, the highest in 
the land, in an Arrest of 7 July 1746 condemned the book to be torn up 
and burned ... by the High Executioner as scandalous, and contrary to 
Religion and Morals, In amplification of this decree the Parlement declared 
that the Pensees philosophiques presents to restless and reckless spirits the 
venom of the most criminal and absurd opinions that the depravity of 
human reason is capable of; and by an affected uncertainty places all re- 


ligions on almost the same level, in order to finish up by not accepting any. 42 
The Parlement might have been better advised to spare itself such tre 
mendous ejaculations, for they simply served to draw attention to skeptical 
ideas and to the author who expressed them. People quickly learned so 
many in French society were leisured and unoccupied who the putative 
author was, and the ideas set forth immediately took on some of the de 
licious savor of forbidden fruit. Ideas, especially radical ideas, had an unusually 
broad and quick currency in eighteenth-century France, which is perhaps 
the principal explanation why a revolution occurred there rather than in 
some other country where misery, poverty, and inequality were even greater. 
Diderot s work, bold and revolutionary though it was, was by no means 
the first eighteenth-century expression of skepticism about Christianity. Dur- 
ing the first half of the century there circulated in France a very large 
number of manuscript works, the precursors of the flood of printed attacks 
that the presses presently began to pour forth. The circulation of these sur 
reptitious manuscripts goes far to explain the rapid gain of new ideas, and 
the equally rapid collapse o the old, in the years after I750. 43 And the 
number of these manuscripts still extant in French public libraries Pro 
fessor Wade of Princeton found some 102 separate titles, many of them in 
multiple copies is testimony of their pervasion and influence. We can be 
pretty sure that Diderot was familiar with many of these writings, especially 
as manuscripts of two of them, now in the library at Fecamp, were copied 
out in his own hand. 44 

Diderot s book, then, has a close relationship with this underground litera 
ture; 45 but it also had characteristics of its own that made it a landmark 
in the chronic debate between skepticism and faith. The first of these char 
acteristics was boldness, the very boldness of Diderot s allowing it to be 
printed. In eighteenth-century France it was taken for granted that a func 
tion and duty of the state was to punish the expression of opinions against 
Religion/ Therefore the police kept a close watch on authors, printers, and 
booksellers. Inasmuch as a larger number of persons had unavoidably to 
be let into the secret, the risks of printing a book were altogether different 
from the risks involved in the production and circulation of a manuscript, 
If these dangerous writings were printed in Paris, as they frequently were, 
they had to be clandestinely printed, often by unlicensed printers who set 
up their fly-by-night presses in out-of-the-way places and moved them fre 
quently in order to escape the police. Yet some of these clandestine and 
peripatetic printers were themselves secret agents of the police. 46 By printing 
a work, one certainly ran a great risk of betrayal. But on the other hand, the 


very act of printing increased the circulation of one s work and extended its 

The Pensees philosophiques evidently found a considerable number of 
readers. In spite of the attempt of the Parlement of Paris to suppress the 
book, at least ten editions were published in the eighteenth century, plus 
five books that quoted it in entirety for the purpose of refuting it (a signally 
obtuse way of spreading the flames while trying to extinguish them), plus 
five printings in collected editions of Diderot s works, plus a translation into 
German. 47 Moreover, in contrast to practically all of the clandestinely cir 
culated manuscripts, which had a decided tendency to be tedious and humor 
less, Diderot s was written with an epigrammatic concision and a sort of 
grave yet gracious persuasiveness that made his book very effective.* The 
tradition in his family was that he dashed off the Pensees philosophiques 
between Good Friday and Easter of I746. 48 This is not impossible, consider 
ing that the sixty-two sections of the work comprise about ten thousand 
words; but it is not very likely, in view of the polish and literary elegance of 
the aphorisms. They have a gloss and quotability that indicate deliberation 
4nd care. 

In skill of composition, as well as in boldness of publication, Diderot s 
Pensees philosophiques quickly achieved a position of pre-eminence in its 
genre. In the form of aphorisms it covered a good deal of ground, much of 
it no doubt suggested by the writings of Shaftesbury. 49 The tenor of the whole 
book is deistic, which is equivalent to saying that it suggests that what man 
can discover about God is made known by reason rather than by revelation. 
Some examples of the aphorisms will speak for themselves, and give some 
notion of the impact they must have had: 

To judge from the portrait people paint me of the Supreme Being, from His in 
clination to anger, from the rigor of His vengeance, from certain comparisons 
that express the ratio between those whom He allows to perish and those to whom 
He condescends to stretch out a hand, the soul the most upright would be tempted 
to wish that He did not exist. . . . The thought that there is no God has never 
frightened anyone, but rather the thought that there is one, such as the one that 
has been described to me (Pensee IX). 

Superstition is more injurious to God than atheism (Pensee XII). 

What is God? A question which is asked of children, and which philosophers 
have a great deal of trouble in answering (Pensee XXV). 

*An English translation is contained in Margaret Jourdain, Diderot s Early Philosophical 
(Chicago, 1916), 27-67. 


People have a right to demand of me that I seek the truth, but not that I find it 
(Pensee XXIX). 

Skepticism is the first step toward truth (Pensee XXXI). 

In this little work Diderot defends the passions (Pensee I), a very sig 
nificant position to take against the prevailing ascetic view held by orthodox 
Christian doctrine; he shows himself very anti-Jansenist (Pensees XIII, 
XIV) and therefore very opposed to the views expressed by Pascal in his 
famous Pensees; 50 he quotes Julian the Apostate with complacency, which 
was enough, of course, to infuriate the orthodox; if he is not an atheist 
and he claims in this work that he is not, saying, f l was born in the apostolic 
Roman Catholic Church; and I submit myself with all my strength to its 
decisions (Pensee LVIII) he certainly defends those who are (Pensees 
XV, XXI); he casts doubts on miracles (Pensees XLVI, LI, LIII, LIV), an 
attack regarded by some critics as the most aggressive and the most telling, 
as well as the hardest to answer, in the whole book; 51 by arguing from the 
evidence of current studies in natural history and biology, he throws new 
light on metaphysical and theological problems, thus making his book a 
remarkably original contribution to the literature of deism (Pensees XVIII, 
XX, XLV) ; and in Pensee XIX he gives a sort of preview of his philosophy 
of the origin of things, which he was to develop at greater length in later 
works. 52 

Diderot became very skillful in the art of writing dialogue, and there 
are some critics who feel that the Pensees p kilo sop hiques is a conversation 
among an atheist, an orthodox Christian, and a deist. Both the atheist and 
the Christian are confounded by the deist, and the book, in spite of its ap 
parent looseness of construction, thus has an underlying unity. 53 

Diderot s book was important enough to draw considerable enemy fire, 
but this counter-bombardment gives the impression of having been more 
effective in betraying its own positions than in damaging its assailant. 54 The 
defenders of orthodoxy probably realized that their antagonist was redoubt 
able: some of them acknowledged his book to be passably well written in 
a spirited, energetic, and sprightly style. 65 Nor was this the last time that 
they would have occasion to make such a rueful admission. 


The Emerging Philosophe 


k s DIDEROT tried to discover for himself a satisfac- 
.tory philosophy of life, his mind encountered 
trammels imposed by orthodox, revealed religion. His early works are more 
concerned with an examination of the truths of religion than his later 
ones, and there is a consistent directional trend in these first writings. From 
the theistic belief in a providential God, which we can see in his notes 
to the translation of Shaftesbury s Inquiry concerning Virtue, Diderot pro 
ceeds to a somewhat militant deism in the Pensees philosophiques, ending 
that little treatise with the suggestion that natural religion, revealed to us 
by our reason, is the best. From this point, as we shall see, he proceeds until 
he arrives finally at a position of outright atheism. 

Anyone not well acquainted with a mind like Diderot s might suppose 
that he adopted skepticism and, later, atheism simply out of a desire to shock, 
to irritate, or to amuse. In reality, he went through this process of emancipa 
tion not to be impudent but to satisfy a sort of intellectual necessity. From 
first to last Diderot sought to understand the universe in which he lived, 
and in so doing he always seemed impelled to follow a principle that one 
might call the principle of greatest possible economy. Diderot was ever 
reluctant to make greater metaphysical assumptions than were necessary to 
provide a rational explanation of the world. Thus he found himself giving 
up Christian tenets simply because he did not find them indispensable and 
essential: If there were a reason for preferring the Christian religion to 
natural religion, he wrote, it would be because the former offers us, on the 
nature of God and man, enlightenment that the latter lacks. Now, this is 
not at all the case; for Christianity, instead of clarifying, gives rise to an 
infinite multitude of obscurities and difficulties. 1 Thus he passed from 
orthodox Christianity through phases of theism and deism to end in a 
basic physiological, psychological, and neurological materialism that left God 



out simply because the existence of God was unnecessary, according to this 
view, to explain the universe. 

In the Pensees philosophiques Diderot purported to regard himself as 
still a Roman Catholic (Pensee LVIII). The last thought of all, however, 
showed him developing the deistic argument that natural religion was best. 
This theme he amplified in a short work entitled De la Suffisance de la 
religion naturelk ( On the Sufficiency of Natural Religion ), which was 
not published until 1770.2 Assezat and Tourneux, editors of Diderot s works, 
assert that this brief essay was written in 1747, following his Sceptic s Wd\, 
although they adduce no evidence to substantiate their assertion. On the 
other hand, the title and argument of the Sufficiency of Natural Religion 
are so organically connected with the Pensees philosophiques that it seems 
likely that the little treatise was written in 1746 or early 1747, thus preceding 
the Sceptics Wal\ f which in several respects is the more radical of the two. 3 

It is interesting to speculate why Diderot made no attempt to publish this 
little series of apothegms on natural religion. Perhaps he felt that they repre 
sented only a dialectical moment in the development of his thought. In this 
brief work Diderot speaks frequently of natural law, graven in the hearts 
of all men/ much as Saint Paul spoke of it in the Epistle to the Romans; 
he declares that religion best that best accords with the goodness and the 
justice of God; and he ends by saying that the truth of natural religion 
is to the truth of other religions as the testimony that I discover within 
me is to the testimony that I receive from someone else; as what I feel to 
what I am told; as what I find written within me by the finger of God, to 
what vain, superstitious and lying men have written on paper or chiseled 
in marble. . . . 4 This sort of argument was common among English deists, 
not at all unknown among French seventeenth-century freethinkers, and 
became quite commonplace in the eighteenth century. Here we see Reason, 
unaided by any reference to the outside world of phenomena, constructing by 
itself a sort of intellectual fabric. This type of ratiocination, so characteristic 
of one aspect of the Age of Reason, was nevertheless not at all characteristic 
of Diderot: his efforts to understand reality were guided not by turning the 
reason in upon itself, but by relating his mind and understanding to the 
physical, biological, and psychological phenomena of the outside world. Thus 
the eleven pages of the Sufficiency of Natural Religion, although interesting, 
are scarcely a characteristic work. And it may be that this was why Diderot 
did not seek to publish it. At all events a more dangerous work was soon 
to come. 

In 1747 Diderot was living with Anne-Toinette and their infant son in 


lodgings in the Rue Mouffetard, only too glad if the police did not know 
who he was or his family at Langres did not know where. No doubt it was 
exciting to be the author of a book that had been burned by the public 
executioner, but it was dangerous, too. A less daring man might have deemed 
it prudent to wait a while before committing to paper doctrines that were 
even more inflammable. But Diderot had that itch for writing that is the 
blessing, and sometimes the curse, of a prolific man of letters, so that an 
incendiary successor to the Pensees philosophiques and the De la Suffisance 
de la religion naturelle presently began to flow from his quill. This was an 
allegory, almost certainly written in 1747, which he called La Promenade du 
sceptique ( The Skeptic s Walk 5 ), with a sub-title describing it as a con 
versation concerning religion, philosophy, and the world. 5 

In the preliminary discourse to his allegory, Diderot shows his awareness 
of the risks run by any author who does not limit himself to the banal. 
Aristes, the supposed author, examines all the disadvantages of attempting 
to publish so controversial an item. One of his imagined interlocutors was 
of the opinion that it was better to be a bad author left unmolested than a 
good author persecuted. But Aristes, a Diderot-like figure, was reluctant to 
accept that choice. There was a solution to the dilemma, though rather a 
drastic one, inasmuch as it involved self-exile and putting oneself into the 
formidable hands of Frederick the Great: Appeal to ... the philosopher- 
prince whom you . . . recently heard scolding Machiavelli with such elo 
quence and good sense.* Pass into his States with your work and let the 
bigots rage. ft 

This advice to an author who is a sort of mirror-image of himself may 
reveal uneasiness on Diderot s part as to his own tranquillity. Police records 
show that he would have been completely justified in being apprehensive. 
On 20 June 1747, a man named Perrault wrote to Berryer, the Lieutenant- 
General of Police, denouncing this miserable Didrot as a very dangerous 
man who speaks of the holy mysteries of our religion with contempt. 7 
Two days later more ample information came in, this time from the priest 
of the parish in which Diderot lived, a man who stated that he had previously 
written to Berry er s predecessor in complaint of Diderot. M. Diderot is a 
young man who passed his early life in debauchery. At length he attached 
himself to a girl without money, but of social position, it seems, equal to 
his, and he married her without the knowledge of his father. The better to 
hide his so-called marriage, he has rented lodgings in my parish at the 
house of M. Guillotte [Guillotte and his wife were the godparents of the 

* Frederick s Anti-Machiavel was published in 1740. 


second Diderot child]; 8 his wife goes by her maiden name. . . . The re 
marks that Diderot sometimes makes in this household amply prove that he 
is at least a deist. He utters blasphemies against Jesus Christ and the 
Holy Virgin that I would not venture to put in writing. ... It is true that 
I have never spoken to this young man, that I do not know him personally, 
but I am told that he has a great deal o wit and that his conversation is 
most amusing. In one of his conversations he confessed to being the author 
of one of the two works condemned by the Parlement and burned about 
two years ago. I have been assured that for more than a year he has been 
working on another work still more dangerous to religion/ 9 

This still more dangerous work, La Promenade du sceptique, described 
three separate paths and what took place on each. These were the paths o 
thorns, of chestnut trees, and of flowers, referring respectively to orthodox 
Christianity, philosophy, and life s more carnal enjoyments. The allegory 
about Christianity is particularly searching and savage, giving in very thin 
disguise a critical account of Biblical history and Christian institutions. The 
residents of this path of thorns are described as soldiers each equipped with 
a blindfold that is to say, the symbol of faith and a white robe, the 
symbol of innocence. They anxiously grope their way through life. The 
soldier s duties are limited to keeping his blindfold on right and keeping his 
robe from getting spots. 10 

The path of the chestnut trees provides a tranquil abode, and resembles 
very much the ancient Academy. Here the mirror-image of Diderot heard 
representatives of the principal philosophical schools the Tyrrhenians, the 
skeptics, the Spinozists, the Berkeleyan idealists or solipsists, the atheists, and 
the deists engage in a discussion that critics regard as the solidest part of 
Diderot s allegory. Not infrequently the path of the chestnuts was invaded 
by the truculent soldiery of the path of thorns. Under our chestnut trees, 
the chiefs of the path of thorns are tranquilly listened to; their thrusts are 
expected and are parried, they themselves are brought to earth, they are 
confounded, they are enlightened, if possible; or at least their blindness is 
lamented. Gentleness and peacefulness regulate our proceedings; theirs are 
dictated by fury. We employ reason, they accumulate fagots. They preach 
nothing but love, and breathe nothing but blood. Their words are humane, 
but their hearts are cruel. u 

The description of the path of chestnut trees incidentally reveals that it 
was a place of men without women. This is quite enough to explain why 
Diderot s mirror-image found himself spending some time in the path of 
flowers. In this rather conventional and final part of the allegory, the burden 


of the argument is that all is not entirely well in the flower-strewn path. 
Proof of this contention rests in three little stories, written almost in dialogue 
form, about a man who swears eternal love to his mistress and then forgets 
her, about another who steals his friend s mistress, and about a third who 
by intrigue secures an appointment that he had learned about from a friend 
who had supposed he was going to get it himself. It is evident that Diderot 
recommended, if one had the resolution to do it, staying in the shade of the 

Diderot s aptitudes were not best suited to the allegory, a literary form 
that he himself later described as the ordinary recourse of sterile minds/ 12 
It may be that in experimenting with this form he was following the ex 
ample of Swift in The Tale of a Tub, especially since we know that he 
was familiar with some of Swift s works. 13 It is interesting and significant 
that in La Promenade du sceptique he frequently seems on the point of 
breaking forth into the dialogue form, which later became his most effective 
and personal mode of expression. Indeed, another allegorical satire of Chris 
tianity that he is believed to have written about this time, a short tale called 
Quen pensez-vous? ( What Do You Think? ), is almost all in conversa 
tional form. 14 Although La Promenade du sceptique is not regarded as one 
of Diderot s major works, still it is by no means without interest: it shows 
the vigor and variety of his imagery; 15 it reveals the breadth of his reading, 
with references to Milton, Montaigne, Rabelais, and many others, besides, 
of course, a considerable familiarity with the history of philosophy; it reveals 
his usual dislike of the Jansenists; 16 it shows him already interested in the 
intellectual problems raised by a person s being deprived of one or more of 
his senses, problems which were presently to provide the central considera 
tion of his Letter on the Blind; 1T and, finally, it again reveals his awareness 
of the impact of biological fact upon metaphysical speculations, a character 
istic destined to make him perhaps the outstanding thinker of his century 
in the philosophy of science. Because of this emphasis on biological nature 
he eventually came to be a philosophical materialist, as we shall presently 
see. But for the moment it caused him to rest at a halfway station between 
the idea of a deistic universe with Voltaire s watchmaker God, on the one 
hand, and an atheistic one with no God at all, on the other. 18 This halfway 
station was a universe that makes God and nature the same thing, the 
position known as pantheism. 

Presumably Diderot hoped to publish La Promenade du sceptique. But 
the police, one way or another, prevented it. According to one version, 
Diderot, without having to surrender the manuscript, was nevertheless 


forced to promise the Inspector of Publications, one Joseph d Hemery, that 
it would not be published. 19 This story would seem to be confirmed by 
Diderot s deposition, when he got into trouble in 1749, that although he had 
written La Promenade du sceptique, he had subsequently destroyed the 
manuscript. 20 But another version of the story, this one told by Mme de 
Vandeul, is that D Hemery searched Diderot s house, found the manu 
script, and carried it away. 21 This version is confirmed by the fact that 
Diderot is known to have tried to get the manuscript back some thirty 
years later, when he was considering the publication of a collected edition 
of his works. 22 The result of his failure to repossess the work was that the 
world had to wait until 1830 before the allegory was published. And Diderot s 
fond recollection began to play him tricks, so that he came to believe that 
this was one of his best works, which is very far from being true. 23 

In writing about the path of flowers, Diderot described Aristes as meeting 
a beautiful woman, of whom he speaks in the somewhat rueful and wise- 
after-the-fact tone of a man looking back upon some untoward experience 
begun in a night club or bar. She was a blonde, he wrote, but one of those 
blondes that a philosopher ought to avoid. 24 We wonder if Madeleine 
d Arsant de Puisieux was a blonde or if, at least, Diderot did not eventually 
come to think that she fitted the specification. For a time, however, Diderot 
was quite under the spell of this rather demanding young Parisienne, a 
woman seven years his junior. She was the wife of Philippe Florent de 
Puisieux, a non-practicing lawyer who did a great deal of translating, espe 
cially from English. 25 It is impossible to say just when the relationship be 
tween her and Diderot began. His reference to loving a number of objects 
very passionately/ including my mistress/ had appeared by March ij^. 26 
But this may not betoken more than Diderot s Gallic feeling that if a 
mistress did not exist, it would be necessary to invent one. Perhaps the ap 
proximate chronology can be established indirectly : in 1751, Mine de Puisieux 
published a book in which she speaks quite transparently of Diderot and 
mentions five years of familiarity/ 27 If the liaison lasted five years, then it 
must have begun not later than 1746. This would agree with the story as 
told by Mme de Vandeul, who says that Diderot wrote his Pensees philoso- 
phiques at Eastertime in 1746 in order to procure money for his mistress. 28 
Probably this is substantially correct, although it must be confessed that Mme 
de Vandeul s account of the Puisieux affair is demonstrably incorrect in 
another particular, and consequently may be so in this one. For she claims 
that Diderot took Mme de Puisieux for his mistress during the absence of 
Mme Diderot at Langres, whither her husband had sent her in the hope 


of being able to reconcile his family to the marriage. 29 The fact is that there 
is documentary evidence that as late as September 1749, Diderot s father 
did not know that his son was married, and therefore the visit that Mme 
Diderot made to Langres in 1752 seems to have been her first. 30 Evidently 
someone in Diderot s family, whether his daughter or himself, was ashamed 
of his taking a mistress and consequently fabricated this tale, thinking that 
the plea of connubial privation would palliate the offense. 

The little that is known of Mme de Puisieux has about it a disagreeable 
and distasteful flavor. Of her it has been said with too patent humour, 
wrote Lord Morely, that she was without either the virtue or the merit 
on which her admirer had just been declaiming/ 31 Mme de Puisieux be 
came a writer of books, no doubt encouraged by Diderot. She was an 
ambitious authoress, full of vanity and intellectual presumption, as her 
various prefaces and introductions show, and it galled her very much to be 
thought to have relied on Diderot for any literary assistance. Thus she is 
at very special pains in her preliminary discourse to her first book, Conseih & 
une amie t to assert that M. D * * * had nothing to do with the writing 
or revision of her work. 32 Nobody believed her: the entry under her name 
in the police records of the office of censorship declared that it is Diderot, 
her very good friend, who did all the body of this book/ 33 The Abbe Raynal, 
author of a fortnightly news letter, wrote to his subscribers, I do not know 
whose book this is, but I am sure that it has been corrected by M. Diderot 
. . . / 34 When the world proceeded to say the same thing about her second 
book, Les Caracteres, the lady became shrill: When [the first part of] the 
Characters appeared last year, people were disposed ... to attribute it to 
a savant who, removed from the world, glories in ignoring its maxims. . . . 
If the Editor of the Encyclopedic is capable of worthily completing so great 
a work, it would perhaps be impossible for him to compose any as futile as 
mine. . . / 35 (These words were published in 1751, and betokened quite 
evidently that the love aflfair had ended in bitterness and despite.) As 
for her protestations of originality, critics observed that her later works, 
with such unremembered titles as Alzarac, Histoire de Mile Tervillc, 
Memoires de la comtesse de Zurlac, and Zarnor et Almanzine, did not 
have the sparkle, nor fulfill the promise, of the early ones. The works on 
morals, by which Mme de Puisieux signalized her first steps in the career 
of letters, wrote a mild and not unsympathetic critic, acquired for her a 
glory that she has not been able to dissipate by her novels/ 36 Mme de 
Puisieux survived until 1795, consumed by vanity to the end. A person who 
met her when she was sixty years old spoke of her ridiculousness/ and her 



deficiency in judgment and intellectual power, although she was evidently 
convinced o possessing both to a superlative degree. By that time Mme de 
Puisieux was stooped and becoming toothless, but she kept up all the little 
airs and affectations that are scarcely tolerable even in a young girl/ 37 

Diderot s love for Mme de Puisieux was consuming, as he himself con 
fessed in a letter to Voltaire in 1749, saying that he was governed by a 
violent passion that has me at its almost complete disposition/ 38 Such an 
attachment naturally had an upsetting effect in his own home. My grand 
mother died/ wrote Mme de Vandeul, my mother remained alone, without 
companionship. The alienation of her husband doubled the grief of her 
loss; her character became melancholy, her disposition less gentle. . . . Had 
her tenderness for my father been able to weaken, her life would have been 
more happy; but nothing was able to distract it for a moment. 

The recollections of Rousseau in his Confessions allow us to see the Diderot 
of this period in close association with a little knot of friends: I spoke to 
Diderot about Condillac and his work; I made them acquainted with each 
other. They were made to get along together, and so they did. Diderot 

undertook to get the bookseller Durand to take the Abbe s manuscript 

As we lived in districts very far from one another, we used to meet, all 
three of us, once a week at the Palais-Royal, and then go to dine together 
at the Hotel du Panier Fleuri. It must have been that these little weekly 
dinners were extremely pleasing to Diderot, for he, who used to miss almost 
all his appointments, never missed one of these. I was then forming the 
project of a periodical paper, to be called Le Persifteur, which Diderot and I 
were to do by turns. I sketched out the first number, and that made me be 
come acquainted with D Aleinbert, to whom Diderot had spoken about it. 
But unforeseen events blocked us, and the project remained where it was/ 40 

The power of Paris to draw to itself the talents of France is exemplified 
by the association around the table of the Panier Fleuri of these four young 
men D Alembert, the Parisian foundling; Condillac, the nobleman from 
Lyon; Rousseau, the plebeian from Geneva and Annecy; and Diderot, the 
bourgeois from Langres. Thus it had been for centuries in university 
and intellectual affairs since the time of Peter Abelard, in political and social 
life at least since Francis I and the Age of the Renaissance and the time of 
Montaigne. A present-day map of the railways of France, all converging 
on Paris, is a chart, so to speak, of the intellectual history of France for the 
past few centuries. In Paris was to be found the stimulating and fructifying 
company of the first-rate, such as the D Alemberts, the Condillacs, the Rous- 


seaus, and the Diderots, teaching one another, exciting one another, profiting 
from the intellectual facilities and reveling in the history and monuments 
of so great and so venerable a city. Of all of this Diderot was now a part. 
He was a bourgeois de Paris, as the birth certificates of his children de 
scribed him. As he walked (if he took the closest route) from the Rue 
Mouffetard to his weekly rendezvous at the Palais-Royal, he would pass, 
as a tourist might do today, the great old church of Saint-Etienne-du-Mont, 
where Pascal and Racine are buried; the Pont-Neuf, where Henri IV was 
assassinated; and Saint-Germain-FAuxerrois, where the tocsin sounded for 
the Massacre of Saint Bartholomew s Day. As he walked the streets of Paris, 
he may often have recalled Montaigne s words about the city, words he 
probably knew, for Montaigne was one of his favorite authors: 

Paris has possessed my heart since my infancy. I am French solely because of this 
great city, especially great and incomparable in its variety; the glory of France 
and one of the noblest ornaments of earth.* 

The little circle of friends mentioned by Rousseau was composed of men 
all destined to be eminent. Condillac, although handicapped by eyesight so 
poor that it is said he did not learn to read until he was twelve, became the 
leading psychologist of his generation. His specialty was interpreting to his 
countrymen the psychological doctrines of John Locke (although he was 
unable to read him in the original), and carrying these on to further con 
clusions. This sort of speculation placed him on the frontiers of knowledge, 
in the shadow ground between psychology and metaphysics, as may readily 
be seen in his works, for example Essai sur I origine des connaissances 
humaines ( Essay on the Origin of Human Understanding, the book Diderot 
helped get published in 1746). One year younger than Diderot, Condillac 
had taken holy orders in 1740 and, even though it is said of him that he 
celebrated mass only once in his life, he evidently was very careful not to 
write anything that could be proved hostile to the Church. Eventually 
Diderot and he drifted apart, perhaps on this issue. Remarkably enough, 
Condillac, though often quoted in the Encyclopedic, is not listed as having 
contributed any articles. It is hard to believe, considering Condillac s reputa 
tion, that Diderot did not desire him as a contributor, and accordingly it 
may be presumed that Condillac deemed his association with Diderot too 
compromising. Nevertheless, their close association, while it lasted, was of 

Paris a mon coeur des mon cnfance. Je nc suis Francais quc par cctte grande cite, grande 
surtout et incomparable en variete, la gloire dc la France ct Tun des plus nobles ornements du 
mondc. (These words are on the plinth of Landowski s statue of Montaigne, erected in 1937 
on the Rue des Ecoles facing the Sorbonne.) 


great value to both. On Diderot s side this can be seen in his Letter on the 
Blind (1749), a work much more basic in its psychological and metaphysical 
concepts than any previous one. As for the influence of Diderot on Condillac, 
the latter s Traite des sensations (1754) was the result of Diderot s pointing 
out in his Letter on the Blind the apparent congruence of Condillac s pre- 
suppositions with those of the British philosopher, Bishop Berkeley. 41 Diderot 
merely pointed out some troublesome affinities between two works that, 
in all other respects, had no relationship, writes the leading authority on 
Condillac. With an astonishing critical sense, he had foreseen the problem 
which Condillac s attempt involved. 42 

Jean Le Rond d Alembert, of whom we shall hear much, was four years 
younger than Diderot. He was the illegitimate child of one of the most 
celebrated, not to say notorious, women of the eighteenth century, and of the 
Chevalier Destouches, a lieutenant general in the French army. He was 
left a foundling on the steps of the church of Saint-Jean-le-Rond (the baptistry 
of Notre-Dame de Paris), and from this circumstance took his name. The 
wife of a glazier, one Mme Rousseau, took care of him in infancy and 
mothered him into middle age. He remained with her, occupying a modest 
little room in her humble home, until he was forty-seven years of age and 
one of the most famous men in Europe, but without her ever realizing, it is 
said, how celebrated her adopted chick had become. Unlike Diderot, D Alem 
bert was unusually precocious. When only twenty-five years of age, he had 
become an associate member of the Academy of Sciences. At twenty-six he 
published his Treatise on Dynamics, which, according to the principal 
French biographical dictionary, was an event in the history of the sciences. 48 
D Alembert was slight and small in stature, with a marvelously intelligent 
and attractive face, as we see it in La Tour s pastel of him, with a clear 
and piercing falsetto voice which permitted his enemies to hint that he was 
not quite a man, and with a skill at mimicry which was the hilarious delight 
of his companions. 

In this small circle of friends, vis-a-vis the psychologist, the mathematician, 
and the musician (for Rousseau about this time undertook to write the 
articles on musical theory for the projected Encyclopedic), Diderot proved 
his versatility by being profoundly interested and instructed in the specialty 
of each. One earnest of this breadth and competence was an article he pub 
lished anonymously in the October 1747 number of the Mercure de France. 
Entitled Project for a New Organ, 44 it was later republished, under Diderot s 
own name, in his Memoires sur different sujets de mathematiques (1748), 
and excited a good deal of interest on the part of the editor of the Gentle- 


man s Magazine, the leading London review of the day. What Diderot had 
in mind were improvements in the simple hurdy-gurdy bird organs or me 
chanical organs of the time. These instruments for an excellent description 
of the bird organ, see Diderot s own article Serinette in the Encyclopedic 
and the corresponding engraving had a range of only one octave and a 
repertory of only a few tunes. 45 Diderot s principal innovation, simple but 
effective, was designed to increase greatly both the acoustical range and the 
repertory of such an instrument. A barrel organ constructed according to his 
description would permit people, even those unable to play an instrument, 
to set up* quite complicated pieces of music, and thus make music more 
readily accessible to all. Apparently, too, Diderot had in mind the con 
struction of instruments large enough to be played in churches. He also 
suggested a chronometer for accurately indicating tempi, in this respect 
anticipating MaelzeFs metronome. Observing this early interest, it is not 
surprising to learn that, when the Encyclopedic was to be done, Diderot 
assigned to himself the articles on musical instruments, their construction, 
their acoustical characteristics, and the method of playing them. 

Diderot s Project for a New Organ was a very characteristic performance. 
In the first place, it shows him being alertly curious, original, and inventive 
and also reveals a constant fascination in the relation of pure theory to 
applied knowledge and to gadgets. Thus, as he discusses how to place the 
pins on the organ cylinder in order to increase its range, he shows an equal 
awareness of both theoretical and technological problems. Another of Diderot s 
hallmarks was his ability to introduce into a discussion of any subject a 
marked quality of subjectiveness, an intimate revelation of personality 
even in an anonymous article on a technical subject. This quality delighted 
the editor of the London Gentleman s Magazine as much as the proposed 
invention itself. What suggested the notion to the author, who appears very 
well versed in physics and geometry, wrote the editor in the leading article 
of the August 1749 issue, may be seen by the following extract from his work: 
"For my part, who am hardly more bashful, or less curious than a child, 
I had no rest nor ease, till I had examined the first German organ I heard; 
and, as I have no skill as a musician, but am a great lover of music . . . 
it came into my mind . . . that it would be very convenient ... to have 
such an organ, or some other instrument, which might require neither more 
natural fitness, nor less acquired knowledge, and on which one might per 
form all sorts of musical compositions." 46 

Later in the eighteenth century there was a marked improvement, both 
in France and England, in instruments using the barrel-and-pin mechanism, 


but perhaps to attribute this to Diderot would be no more than argument 
on the level of post hoc, ergo propter hoc^ In the Gentleman s Magazine 
for September 1749, a reader from Lancashire inquired whether your ac 
count of M. Diderot s organ has yet set the musico-mechanical artists of 
London at work, or is likely to do so. The design in all probability must 
take. It has many recommendations, one especially, which will weigh both 
with those that are performers in music, and those who are not; I mean 
by having the barrel-pins moveable. 48 It is therefore tempting to believe 
that Diderot s influence was at work during the late eighteenth and early 
nineteenth centuries, when the application of the barrel-and-pin mechanism 
to the organ became very common in England. Indeed, Dr. Scholes, the well- 
known British musicologist, found one of these organs still in weekly use 
in a Suffolk church in 1934 49 

Diderot always delighted in being called a philosopher, or, better yet, the 
philosopher. In many respects he had been qualifying himself for the appel 
lation in the usual sense of the term. For in 1746-7 he was already proficient, 
as his writings show, in the history of philosophy; he was already con 
cerned with problems of ethics, of the nature of God and man s relation to 
Him, and with the problem of being. Already we see him rummaging about 
in the philosophy of science, trying to use mathematical, biological, and 
physiological insights as aids in the investigation of ultimate things. 

But more than this, Diderot wanted to be a philosophe in that special 
sense of the French word which the English does not quite convey. What, 
then, is a philosophe? The answer is not easy, partly because in the eighteenth 
century the word was dynamic and fast-moving. At the beginning of the 
century, according to Muralt, a Swiss who wrote extensively on the man 
ners of the French, the term philosophe was one of reproach and almost 
of insult, betokening a person who desired to live in moody and invidious 
solitude. 50 But fifty years had been changing all that; philosophei declared 
themselves to be as sociable as any other Frenchmen, and the word began 
to take on pleasing connotations. Moreover, it became a party name, with 
all the blood-quickening and adrenalin-stirring attributes that party names 
generate. It is easy to see in part what the philosophes meant by philosophy* 
if we turn to the article Philosophe long regarded as one of Diderot s 
best, in the Encyclopedic. In reality this article was a shortened version of 
one written by some unknown person and first printed in 1743, possibly 
circulated in manuscript form before that. 51 It may be fairly assumed that 
Diderot was likely to have known the piece by this time (1746-7) when he 
was just moving into his responsibilities with the Encyclopedic. His en- 


thusiasm for the article may be inferred from the fact that he published the 
scissors-and-paste version in the Encyclopedic, whether he wrote it him 
self or accepted it from another hand. And the following excerpts from the 
1743 edition, copied almost verbatim in the Encyclopedic, will give some 
idea of what an eighteenth-century philosophe thought himself to be: 
Reason is to a philosopher what grace is to a Christian in the system of Saint 
Augustine. . . . 

The philosophical spirit is, then, a spirit of observation and exactness, relating 
everything to its true principles; but it is not the mind alone that the philosopher 
cultivates . . . Man is not a monster who should live only in the deeps of the 
sea or the depths of a forest ... his needs and well-being engage him to live in 
society. Thus reason demands of him that he know, study, and labor to acquire 
sociable qualities. 

. our philosopher, who knows how to divide his time between withdrawal 
from men and intercourse with them, is full of humanity. He is the Chremes of 
Terence, who feels himself a man and who interests himself in the good or bad 
fortune of his neighbor out of humanity alone. Homo sum, humani a me mM 

dienum puto. . 

Civil society is, as it were, the only divinity that he recognizes on earth; 
he worships it, and honors it by probity, by an exact attention to his duties, and by 
a sincere desire not to be a useless or troublesome member of it. ... 

The philosopher, then, is an honest man who acts in all things according to 
reason, and who combines good morals [moeurs] and sociable qualities with a 
mind disposed toward reflection and preciseness. 52 

From these quotations it is possible to see some of the reasons why the 
term philosophe became a pleasant word in the eighteenth century, resonant 
with such happy overtones. On the affirmative side, it betokened a sense 
of social awareness and responsibility which appealed to the sympathies and 
large-mindedness of many well-intentioned persons. Moreover, the philosophe 
was inherently a man of probity and virtue, par excellence the virtuous man. 
On the negative side, it turned out that to be a philosophe was easy. No 
one need fret over such painful prerequisites as that of knowing the dif 
ference between ontology and epistemology. The ticket of admission to 
the chestnut path bore no pedantic stipulations having to do with a tech- 

The Encyclopldic. more circumspect, reads at this point, For him, civil society is, as it were, 
a divinity on earth . . f 


nical knowledge of the subject. As Professor Dieckmann points out, the 
author of this treatise (and, following him, the party of the Encyclopedists 
in general) does not conceive of the philosopher as the author of a system 
of ideas or the creator of a comprehensive interpretation of the world. . . . 
The philosopher thus conceived appears as a model, an ideal norm after 
which one strives, as one strove during the Renaissance to be an uomo 
universale, or cortigiano, and in the nineteenth century a gentleman / 63 

Diderot was a philosopher. He was also a philosophe. His early writings, 
skilled in the technicalities of the philosophical method, using the word in 
its usual sense, were also beginning quite unmistakably to show the char 
acteristic approach described by the author of the treatise on The Philosopher. 
The philosophe was beginning to emerge. 


The Early History of the Encyclopedic 

French Encyclopedic, as it stands today on the 
J. shelves of library treasure rooms in the select com 
pany of the very old, the very rare, and the very naughty, is an enormous 
work consisting of seventeen folio volumes of letterpress and eleven of en 
gravings, to say nothing of four volumes of supplement, two of index, and 
one of supplementary plates. Yet at its inception the Encyclopedic was a 
modest venture, planned to be no more than a translation in four volumes 
(plus one of engravings) of Ephraim Chambers Cyclopaedia, or Universal 
Dictionary of the Arts and Sciences, a very successful work first published in 
1728 in two folio volumes embellished by twenty-one large plates. It was 
Diderot who in all probability was principally responsible for the expansion 
from the smaller project to the larger one. At the very least, it was he who 
became responsible for seeing it through. And thus was produced, as a modern 
French critic has remarked, not the finest, but surely the most characteristic, 
work of the French eighteenth century. 1 

Previous to that time there were in existence various technical dictionaries 
or dictionaries of classical literature and learning. 2 There had even been a 
Latin Encyclopaedia published in 1630 by Johann Heinrich Alsted, a work 
which treated of philosophy, philology, theology, jurisprudence, medicine, his 
tory, and the mechanical arts. But by the end of the seventeenth century this 
estimable work was outmoded, and no less a person than the great Leibniz 
expressed the hope that a new encyclopedia would soon be forthcoming. 3 In 
view of the continuing spread of knowledge and education in Western Europe, 
a comprehensive reference work was needed that would inform its readers 
of the numerous discoveries in basic science made during the seventeenth 
century and also attempt to guide their understanding of the whole by means 
of some scheme or conspectus of the interrelationships of the several branches 
of knowledge. As we look back on the intellectual preparation of Western 



European society two hundred years ago, we are not surprised that a con 
siderable market existed for such works as Chambers or the more ambitious 

one of Diderot. 

Chambers Cyclopaedia was prefaced by an elaborate scheme of the divisions 
and subdivisions of knowledge. It was the first attempt that had yet been 
made at once to arrange Knowledge by the Alphabet, and to exhibit a view 
of-its relations and dependencies/ 4 features which the French Encyclopedic 
also adopted. Chambers Cyclopaedia was very like a present-day dictionary, 
especially in its emphasis on the definition of common words. There was a 
particular abundance of medical and pharmaceutical terms, but no attempt 
was made to include geographical, historical, or biographical information. 
Moreover, it was severely limited in the number and scope of its engravings, 
which were devoted to such subjects as heraldry, surveying, sun dials, algebra, 
geometry, trigonometry, and navigation. 

The plan and intent of Chambers work was acknowledged by everyone, 
including Diderot, to be exceUent-JThe execution, he contended, left some 
thing to be desired. Though moreTnclusive than any other existing work, it 
was still not comprehensive enough, and its treatment was frequently too 
brief, The entire translation of Chambers has passed under our eyes, wrote 
Diderot in the prospectus of 1750, and we have found a prodigious multitude^ 
of things needing improvement in the sciences; in the liberal arts, a word 
where there ought to be pages; and everything to be supplied in the me 
chanical arts/ 5 So important a subject as Agriculture/ for example, was 
allotted in Chambers thirty-two rather jejune lines. In contrast, the article 
that Diderot wrote on that subject for the Encyclopedic fills fourteen columns 
and, among a host of other topics, gives publicity to Jethro Tull s discoveries 
in new methods of husbandry. This instance shows the breadth of Diderot s 
interests, and reveals also how the Encyclopedic became a forum for new 
ideas. 6 Diderot had a right to say that the articles of Chambers are laid out 
regularly enough, but they are empty; ours, though irregular, are full 1 

In France, during the very years when Chambers was preparing his Cyclo 
paedia for the press, there was formed an ephemeral Societe des Arts (1726), 
which cherished the hope of publishing a sort of encyclopedia in which re 
lated arts, sciences, and mechanical arts would be described. 8 Though re 
vealing the ferment of ideas, this project had no concrete result, nor any 
connection with the later Encyclopedic. Another project that might have 
resulted in an encyclopedic was of Masonic origin. A prominent Freemason 
named Ramsay declared in Paris in 1737 that all the Grand Masters in Ger 
many, England, in Italy and throughout Europe exhort every savant and 


artist in the brotherhood to unite for furnishing materials for a universal 
dictionary of liberal arts and useful sciences, theology and statecraft ex- 
cepted. 9 Moreover, the Due d Antin, Grand Master of the Freemasons in 
France, repeated and endorsed Ramsay s ideas in a .discourse pronounced in 
the Masonic Grand Lodge in I740. 10 Statements such as these naturally have 
caused historians to wonder whether there was not some direct connection 
between Freemasonry and the Encyclopedic, and this supposition has been 
heightened by the discovery that Andre-Francois Le Breton, one of the pub 
lishers of the Encyclopedic, was made a Master Mason in a lodge at Paris 
in I729- 11 No evidence, however, has yet been turned up to suggest that 
Diderot was at any time a Mason. 12 In sum it seems safe to follow the judg 
ment of a leading modern authority on the subject that Masonry and the 
Encyclopedic, however similar in attitude, were born in two different and 
distinct moments as a result of two different and distinct needs in the France 
of the eighteenth century. 13 

Actually, the project for translating Chambers was the result not so much 
of an ideological enterprise as it was a search for profit. In June 1744 Le 
Breton had signed a contract with one Godefroy Sellius, a German from 
Darjzig, for a translation of the works of a German metaphysician, at that 
time of great repute, named Wolff. 14 This project appears not to have 
achieved publication, but in January of 1745 Sellius suggested to Le Breton 
the translation of Chambers Cyclopaedia. Sellius claimed to have found a 
rich and opulent partner, an Englishman named John Mills. In February 
1745, Mills and Sellius entered into a contract, and just a few weeks later the 
two of them contracted with Le Breton to provide a translation, corrected 
and enlarged, of Chambers Cyclopaedia, to consist of four volumes of letter 
press and one of 120 plates. 15 During this time Le Breton was evidently in 
negotiation with the authorities for a license, for there was issued in blank 
on 25 February- 1745 a license good for twenty years, which, in the further 
processes of being sealed and spread on the records of the corporation of 
booksellers, on 26 March and 13 April respectively, lost its anonymity and 
appeared in Le Breton s name. 16 

On the strength of these preparations, a prospectus was printed in the 
spring of 1745, antedating by five years the more famous one that Diderot 
launched in 1750. This comparatively unknown prospectus of 1745, an 
nouncing an Encyclopedic, ou Dictionnaire universel des arts & des sciences, 
is a great rarity among book collectors. 17 Besides stating the terms of sub 
scription, the prospectus emphasized its intention of providing a polyglot 
cross-reference system for the titles of articles, and included some sample 



articles, translated from Chambers, such as Atmosphere/ Table/ Blood/ 
and Dyeing. Several would-be subscribers presented themselves at once, 18 
and the Journal de Trevoux, in its number for May 1745, quite outdid itself 
in the warmth of its remarks. To judge by the Prospectus/ it wrote, . . . 
there is nothing more useful, more abundant, better analyzed, better related, 
in a word more perfect and finer than this Dictionary; and such is the gift 
that M. Mills is making France, his adopted country, while doing honor 
to England, his true one. 19 

John Mills lived to become an appreciated writer on agricultural affairs 
in England, and the Dictionary of National Biography speaks of him with 
approbation. His relations withLe Breton, however, were exceedingly stormy, 
and ended in an exchange of blows on 7 August 1745. Mills, apparently, had 
misrepresented both his financial situation and his command of the French 
language. Moreover, Le Breton had supposed that his own relation with 
the enterprise would be merely as printer and agent rather than entrepreneur. 
It was necessary, for instance, that some French citizen be the intermediary 
for Mills and Sellius, both of them foreigners, in negotiations with the 
authorities for a license. Le Breton declared, when he printed his side of the 
story, that the translations by Sellius were so poor that they could not be 
used, that Mills was remiss and tardy in the revision of these articles, and 
that meanwhile he, Le Breton, was so frequently asked for advances in 
money that he became convinced that Mills and Sellius were making him 
their dupe. 20 Mills s urgent demand in August for a very large sum of 
money, coupled with Le Breton s discovery that far from being an heir to a 
large estate, Mills was only a sort of clerk in the Paris branch of a British 
bank, led to that kind of mutual explanation that is likely to end in an 

Suit and countersuit were filed after the quarrel. Mills asserted that Le 
Breton had not only hit him in the stomach and struck him twice over the 
head with a cane, but had also cheated him of subscription money and was 
intriguing to get sole possession of the copyright. 21 Le Breton said, among 
a number of things, that he taught this arrogant Englishman that a French 
man, if insulted, even though his weapons be inferior, avenges himself at 
once, as much as in him lies. 22 The case did not come to trial. Instead, the 
Chancellor of France, the highly respected D Aguesseau, one of the most 
famous magistrates in the history of the ancien regime, took direct cogni 
zance of it. Such action was ordinary enough, for the chancellor of France 
was ex officio responsible for censorship and other matters pertaining to 
the policing of the book trade. Le Breton asserted many years later that 


D Aguesseau, upon examining Mills and Sellius, quite easily detected their 
incompetence and their swindling. 23 No damages were assessed against Le 
Breton, and soon afterward Mills left France. 24 

The Chancellor allowed Le Breton to hope that after a short time he would 
be allowed to take up the project again. For the moment, however, the 
Council of State, on D Aguesseau s recommendation, revoked the license 
that had been granted the preceding February, and declared Le Breton s 
contract with Mills and Sellius to be void. The Arrest of the Council of 
State alluded to various infractions of the regulations regarding subscriptions 
committed by Le Breton but specifically mentioned the possibility of se 
curing a privilege anew. 25 

Although the project was now in abeyance, sufficient public interest had 
been aroused by the prospectus of 1745 to encourage Le Breton to resume his 
plans as soon as possible. An earnest of public curiosity is to be seen in the 
remarks of an anonymous author, writing in the Jugemens sur Quelques 
Outrages Nouveaux: What an astonishing, an admirable dictionary is that 
of M. Chambers, entitled the Cyclopaedia, or the Circle of Sciences, which 
ought to be translated from the English into French, and for which sub 
scriptions were even beginning to be taken at Le Breton s, bookseller of 
Paris, but for which the license has been revoked because the enterprise 
has appeared to be poorly planned. It is very much to be hoped that this 
project will be undertaken again without delay, under better auspices, and 
that our French printing industry, which, suffering grievously from the 
hardness of the times, has need of being encouraged and favored, may profit 
from so lucrative an undertaking, for it would be regrettable to see foreign 
countries, protected by the formalities of our regulations, enrich themselves, 
to the great shame of our own industry. 26 

Unable to count upon the rich and opulent Mills but now intent on pub 
lishing a translation of Chambers himself, Le Breton evidently felt that he 
needed more capital. In October 1745 he took into partnership for this par 
ticular venture three of his fellow-publishers, Briasson, the elder David, and 
Laurent Durand. 27 This partnership agreement was supplemented by an 
other in which it was stipulated that Le Breton was to do the printing job 
for the whole venture, and a total edition of 1,625 sets was planned. 28 In 
December 1745, the government renewed the license that had been annulled 
the previous 28 August and this renewal was officially sealed and promulgated 
on 21 January I746. 29 The translation of Chambers Cyclopaedia was once 
more under way. 

It is hard to say when or how Diderot first became associated with the 


project. It may have beea as early as the summer o 1745, for Le Breton 
spoke in his memoir of that year of some unnamed intelligent person who 
was to have corrected the whole Sellius-Mills translation, and without whom 
the Prospectus would not have been welcomed as favorably as it has. 30 
This intelligent person may have been Diderot. Or perhaps it was through 
his publishers, Briasson, David, and Durand, that he became associated with 
the project. Briasson had been the publisher of Diderot s translation of the 
Grecian History; all three of them had collaborated in publishing James s 
Dictionnaire universel de medecine;* 1 and one of them, Durand, was the 
publisher of Diderot s edition of Shaftesbury, off the press that very year. 32 
The entries in the publishers account book of the Encyclopedic show pay 
ments to Diderot beginning in 1746 60 livres in February, 30 livres on 
4 March and 15 on 31 March, 90 livres on 30 April, 120 on I June. 33 At this 
time he was certainly on the pay roll, but still a goodly distance from being 
entrusted with the principal direction of the enterprise. 

It has also been asserted that Diderot was introduced to the project of 
the Encyclopedic by the Abbe Jean-Paul de Gua de Malves, a brilliant but 
eccentric and unstable mathematician. According to the famous Condorcet, 
who wrote a eulogy of Gua de Malves at the time of his death (1786), it was 
the Abbe who recruited Diderot, among others, to assist in the work. 34 Gua 
de Malves, who was described in a secret police report in 1749 as having the 
manner and countenance of a crazy man, first appears in the account book 
of the publishers at the same time that D Alembert makes his appearance 
there December 1745 and a few weeks before Diderot. 35 On 27 June 
1746, the Abbe became the principal editor of the project that became the 
Encyclopedic, by virtue of signing a contract of which Diderot and D Alem 
bert were the witnesses. In accordance with this agreement, he was to 
f extend the part having to do with the arts, preferably, as much as it will 
be possible for him to complete/ 36 Whether or not he had recruited them, 
Gua de Malves retained both Diderot and D Alembert to work on the 
project, assigning to each of them twelve hundred livres, to be paid from 
the total of eighteen thousand livres that he himself was to receive. More 
over, Diderot and D Alembert were to enjoy a sort of veto power in judg 
ment of the accuracy of translation of the English articles. 37 

The new chief editor was a learned man, described in the contract as 
member of the Royal Academy of Sciences, of the Royal Society of London, 
Reader and Royal Professor of Philosophy at the Royal College of France. 
He was also extraordinarily headstrong and stubborn, and, as Condorcet 
says, it would have been difficult for there not to arise frequent disputes be- 


tween a savant who saw in the undertaking only an enterprise useful for 
the perfecting of human knowledge or public instruction, and booksellers 
who saw in it only a business matter. M. 1 Abbe de Gua, whom misfortune 
had made more easily wounded and more inflexible, soon grew disgusted 
and abandoned this work on the Encyclopedic. 38 

In the light of this documentary proof of their association with Gua de 
Malves, it is more than a little odd that neither Diderot nor D Alembert 
ever alluded in their writings to the connection of Gua de Malves with the 
Encyclopedic, leaving us to wonder how much this taciturnity was inspired 
by a deliberate intent to mislead. Just what the relations between him and 
Diderot were can only be inferred, the sole evidence being a single re 
mark about him made by Diderot in his later works, an allusion rather 
ungenerous in tone and one which made no reference to the Encyclopedic. 
Wanting an example of the tendency of some persons to run to extremes, 
Diderot found it in that old abbe one sees on one s walks. . . . the Abbe 
de Gua de Malves. He is a profound geometrician. . . . but in the street 
he does not have common sense. In one year he straitened his income by 
assignments upon it; he lost his professorship at the Royal College; he got 
himself excluded from the Academy, and consummated his ruin by the 
construction of a sand-screening machine that never separated out a single 
particle of gold; returning poor and dishonored, he fell on the way back 
while walking a narrow plank and broke a leg. 39 

The lack of satisfactory evidence for determining to whom should belong 
the credit of first having proposed a much expanded project, Diderot or 
Gua de Malves, has occasioned something of a who-killed-Cock-Robin dis 
pute among authorities. 40 Condorcet, who was personally acquainted with all 
the men involved, uncompromisingly declared that Gua de Malves had 
the idea first. He had had time to change the form of it; it was no longer a 
mere augmented translation it was a new work, undertaken on a vaster- 
plan. 41 However, Condorcet adduces no documentation. Moreover, he 
was writing after the death of all ,the persons involved, so that any misstate- 
ments he may have made were not subject to contradiction. Condorcet says 
that Gua de Malves recruited Diderot and D Alembert, but he also claims 
that Gua de Malves recruited other persons, such as Condillac, Mably, and 
Fouchy, who in fact did not co-operate. There does, then, exist a possibility 
that Condorcet was partially misinformed; and over against his testimony 
can be set that, equally unsupported, of Naigeon, who declared, to bolster 
his insinuation that Gua de Malves s association with the project did not 
amount to much, that the first project . . . was limited to the translation 


of Chambers English Encyclopedia, with some corrections and additions 
that the Abbe de Gua, at that time the sole editor, took upon himself to do in 
order to make up for the important omissions of the English author and 
to finish the table of human knowledge of that epoch. 42 In short, so con 
flicting and defective is the evidence that we are reduced to speculation and 
the weighing of probabilities. Therefore we might say, with great diffidence, 
that it seems more probable that Diderot was recruited by the publishers 
rather than by Gua de Halves; that the latter might very well have recruited 
D Alembert, both of them being mathematicians, and that this may have pro 
vided the occasion for Diderot and D Alembert to become acquainted; that 
both Gua de Halves and Diderot, being persons of learning and imagina 
tion, were capable of conceiving the idea, whether independently or in 
association, of expanding the project; and that Diderot, whether or not he 
got the idea first, unquestionably displayed the large-mindedness necessary 
for success in carrying it out. 

The agreement between the publishers and Gua de Halves lasted some 
thirteen months and then was canceled by mutual consent on 3 August 
!747 There soon followed one of the biggest moments in Diderot s life. 
On 16 October the publishers entered into a contract with him and D Alem 
bert to replace Gua de Halves in the direction of the enterprise. Diderot 
was to get 7200 livres in all: 1200 of it to be paid in a lump sum upon 
publication of the first volume; and the remaining 6000 to be paid at the 
rate of 144 livres per month. D Alembert was also to be paid at the rate of 
144 livres per month, but the total was to be only 2400 livres. Thus the pub 
lishers contemplated a situation in which D Alembert would continue on 
the project only another sixteen months, while Diderot, at this rate of 
payment, would be on the job another three and a half years. 44 

For Diderot the contract of October 1747 represented both independence 
and security. Although a sum of 144 livres per month was modest, he could 
now count on a constant income for the next forty-one months, with two- 
thirds of a year s salary extra and in a lump sum when the first volume was 
published. To know that he could keep the wolf from the door for at least 
four or five years this was indeed something for a person who had lived 
as precariously as he. Actually, in return for this advantage he undertook 
responsibilities that lasted twenty-five years, for not until 1772 did he bring 
out the last volume of plates. In retrospect, Diderot was inclined to think 
that he had been grievously underpaid for his work on the Encyclopedic, 
and that the time it took robbed him of the opportunity for more substantial 
literary accomplishment. Haybe so, though this is far from certain. With- 


out the Encyclopedic he might have become more undisciplined and less 
productive. 45 It must be admitted, however, that the necessity for writing a 
large number of articles in haste developed in Diderot, for better and for 
worse, a flair for a type of writing that may well be called journalistic. At 
its best his writing has a sublime impetuosity and, at its worst, it possesses 
characteristics of the impromptu and the improvised. 

In the six months following the publishers contract with Diderot, so great 
an expansion of plans occurred that it became necessary to ask for a new 
license. There had been no intimation of this during the thirteen months 
that Gua de Malves had been the chief editor of the project at least so 
far as existing documents show and consequently it is tempting to sup 
pose that this expansion came as a result of Diderot s breadth of views and 
persuasive tongue, that gilded tongue of which his mother-in-law had 
spoken more in admiration than anger. On some occasion during the early 
history of the Encyclopedic Diderot had a decisive interview with the learned 
and pious Chancellor d Aguesseau. It is evident that the point of discus 
sion had to do with plans for expanding the Encyclopedic, and that the 
freethinking Diderot impressed the Chancellor very favorably. This was 
the more extraordinary in that the Chancellor, whom Voltaire described 
as a tyrant desiring to prevent the nation from thinking, was customarily 
very stern and very conservative in his administration of the censorship. 46 
But when could this interview have taken place? Probably not when the 
privilege of January 1746 was being mooted, for this month was the first 
in which Diderot s name appeared on the pay roll, and it is clear that he 
was not yet entrusted with any great responsibility in the enterprise. But 
by April 1748, when the new privilege was granted, he was one of the co- 
editors. Therefore it was probably at this time that he astonished D Agues 
seau by his intellectual powers and readiness of wit. At all events the new 
license was registered at the Royal Corporation of Booksellers on 30 April 
1748, thus superseding the previous one of January I746. 47 A comparison of 
the texts of the two documents shows very little difference between them, 
but evidently what difference there was, was considered very significant. 
Whereas the 1746 license set forth that Le Breton intended to publish a 
text translated from the English Dictionary of Chambers and of Harris, 
with some additions, the 1748 privilege calls for a translation of the Eng 
lish Dictionary of Chambers, of Harris, of Dyche, and others, with aug 
mentations. . . , 48 

Lamoignon de Malesherbes, who between 1750 and 1763 was himself the 
magistrate in charge of regulating the book trade, is the source of two ac- 


counts of Diderot s interview with D Aguesseau. The later account, written 
in 1790, is the better known, and is contained in Malesherbes Memoir on the 
Liberty of the Press. Malesherbes recalls that the plan [of the Encyclopedic] 
was concerted with the most virtuous and enlightened of magistrates, the 
Chancellor d Aguesseau. M. Diderot was presented to him as that one 
of the authors who would have the greatest share in the work. 
This author was already marked, by many of the pious, for his freedom 

of thought. 

However, the pious M. d Aguesseau wished to confer with him, and I 
know that he was enchanted by certain marks of genius that shone forth 
in the conversation. . . . 49 

The other account by Malesherbes of Diderot s interview with the Chan 
cellor was written at a date much nearer to the event. In an unsigned and 
undated memorandum, written in Malesherbes unmistakable and almost 
illegible hand, and which internal evidence shows to date from 1758 or early 
1759, Malesherbes wrote that The late Chancellor had cognizance of this 
project [the Encyclopedic]. Not only did he approve it, but he corrected it, 
reformed it, and chose M. Diderot to be the principal editor of it/ 60 

Many years later Diderot wrote a cryptic declaration that might possibly 
refer to his relations with D Aguesseau. I protest/ he wrote, that under 
taking the Encyclopedic was not of my choosing; that a word of honor, very 
adroitly exacted and very unwisely granted, bound me over, hand and foot, 
to this enormous task and to all the afflictions that have accompanied it 
, . . / 51 Whether or not this remark by Diderot refers to D Aguesseau, one 
observation should be made concerning Malesherbes statements. If Males 
herbes memory was more accurate in the account he wrote while still in 
office while he still could refresh his memory from the office records 
about an event that had happened only ten years previously than it was 
in the account written thirty years later, then it appears that the Chancellor 
did more than simply accept Diderot as an editor. Rather, D Aguesseau 
chose him, thus investing him with some of the Chancellor s great prestige 
and authority, and making it more difficult to attack the Encyclopedic on 
ideological grounds. If so, this interpretation of events would go far to 
explain why Diderot, at that time a person still quite obscure, seems to have 
been so quickly accepted by both friend and foe as the leader of the great 
new enterprise. 


Two Very Different Books 


L s HIS thirty-fifth birthday approached, Diderot s 
.time was filled by a variety of activities. Three 
rather cryptic entries in the publishers account book for June, July, and 
August 1748 suggest that he may have been concluding his translating work 
on the James Medicinal Dictionary}* In addition, his new job as one of 
the chief editors of the Encyclopedic involved not only the translation and 
adaptation of a host of articles from Chambers Cyclopaedia, combined with 
much planning for a greatly extended project, but carried with it con 
comitant necessities of looking about for collaborators and directing them 
in their assignments, 2 Documentary evidence of the minutiae of this im 
portant and time-consuming work has practically all disappeared. No doubt 
discarded in wastebaskets and trash fires as useless, the concrete evidence 
of the process of editing the notes exchanged between editor and con 
tributor, the manuscripts of proffered articles with perhaps Diderotian blue- 
pencilings upon them, the galley proofs, the page proofs has almost com 
pletely vanished. Nevertheless, there must have been an exhausting amount 
to do, especially as the Encyclopedic was planned to be the result of the labor 
of a company of men of letters. And in addition to these tasks Diderot 
found time, or at least some time, for his domestic life with Anne-Toinette 
and baby Fran^ois-Jacques-Denis back at the lodgings in the Rue Mouf- 
fetard; probably a good deal more time for Mme de Puisieux, and for his 
expanding circle of friends; and, finally, time snatched somewhere or other 
for the composition of one more in his series of risky and as regards this 
particular work risque manuscripts. 

This was the novel called Les Bijoux indiscrcts ( The Indiscreet Jewels ). 
According to Mme de Vandeul, the book was written in a fortnight on a 
sort of wager with his mistress to show how easy it was to do this sort of 
thing. 3 The novel, having been bought by the publisher Durand for twelve 



hundred livres, was on sale, under the mantle or under the counter, in the 
early days of 1748.4 This is about the time negotiations were under way with 
the Chancellor of France for a license for an expanded Encyclopedic. It was 
lucky for Diderot that D Aguesseau, whose official duties were in some re 
spects like those of a censor in old Roman times and whose temperament 
somewhat resembled that of Cato the Elder, was unaware of this excursion 
into the field of salacious literature. 

Part of the interest and the daring of the book lay in its transparent 
allusions to living figures. The action is supposed to take place in the Congo 
at the capital city of Monomotapa (a name made familiar by the opening 
line of one of La Fontaine s fables), and the principal personages are the 
Sultan Mangogul and his charming favorite, Mirzoza. One did not have 
to be a medium to understand that the author had in mind Louis XV and 
Mme de Pompadour, who had become the King s acknowledged mistress 
three years earlier. The book is also filled with thinly disguised references 
to Paris, the Opera, France and England, and to such personages as the 
Due de Richelieu, Cardinal Fleury, the composers Lully and Rameau, 
Descartes, Newton, and Louis XIV. This in itself was sufficient to make the 
book audacious. Over and above this was the plot. The Sultan, to fend off 
boredom, to which he was unusually subject, was given a magic ring. This 
ring had the property, when turned toward any woman, of making that 
part of her anatomy talk which, if it ordinarily had the power of speech, 
would be most qualified to answer a Kinsey questionnaire. To a novelist 
perhaps unsure of his ability to write a tightly constructed novel, this plot 
was admirably calculated to keep up suspense. If interest flags, just bring in 
another trial of the magic ring. Diderot did so. There were thirty trials in 
two volumes, all of them attended by what might be called success. 

There is a tradition that Diderot got the idea for his novel from a novelette 
entitled Nocrion, conte allobroge. This item, now exceedingly rare, was pub 
lished in 1747 and written, perhaps by the Count de Caylus, perhaps by the 
Abbe (later Cardinal) Bernis, in the naive manner and archaic language of 
a medieval fabliau. 5 Certainly Diderot could very well have taken from 
Nocrion the principal device of Les Bijoux indiscrets. But whether or not this 
was the source of Les Bijoux, Diderot, of course, did not invent the genre 
of licentious novels. Indeed, a very successful practitioner in this field, or 
perhaps swamp, of letters was living in Diderot s day ~ Crebillon the 
Younger, whose most famous novel, Le Sopha, had been published in 1740. 
Obviously there is a great similarity of device in the plots of Crebillon s and 
Diderot s novels. And there is a similarity of cynicism, too, in their common 


assumption that every woman, however demure and virtuous she may seem, 
is really morally corrupt. 

Diderot would not have been Diderot if he had not strewn this work with 
a large number of thoughtful observations and lively criticisms of the social 
and intellectual life of his time. In consequence, no serious student of Diderot s 
ideas and their development can afford to overlook Les Bijoux indiscrets* 
For example, the book contains a very good comparison and contrast of the 
music of Lully and Rameau (chapter xiii) ; there is also a critical animad 
version to Louis XIV concerning his domination by Mme de Maintenon, 
and a disapproving reference to his Revocation of the Edict of Nantes 
(chapter i); there is a parody of a sermon which quite makes us believe 
Mme de Vandeul when she states that in the early years of vagabondage 
at Paris her father got fifty crowns apiece for six sermons written for the 
missionary who was going to the Portuguese colonies (chapter xv); there 
is much interesting speculation about the nature of dreams and the real 
character of the soul (chapters xlii and xxix) ; 7 the scientific and meta 
physical views of the Newtonians are contrasted with those of the followers 
of Descartes (chapter ix) ; there is a good deal of criticism of the theater, 
views praised by Lessing, the great German playwright and critic, and 
which are the blood brothers of Diderot s later writings on the theater 
(chapters xxxvii and xxxviii) ; 8 and a chapter of literary criticism, rather 
redolent of Swift s Battle of the BooJ^s, in which Homer, Virgil, Horace, 
Pindar, Socrates, Plato, and Voltaire are admiringly mentioned and the 
Quarrel of the Ancients against the Moderns warmed up again (chapter xl). 

Critics speak with great interest and respect of a chapter set forth as a 
dream, which really deals with the triumph of the scientific method over 
ignorance posing as knowledge. 9 It was like Diderot to include so serious 
a subject in a frivolous and licentious novel, telling it in the form of a 
dream or myth as Plato might have done. This was chapter xxxii, called 
by Diderot The best, perhaps, and the least read, of this History. The 
Sultan Mangogul dreamed he had been carried into the Realm of Hypoth 
eses. While there, he saw a child, Experiment, approaching and maturing 
and growing ever bigger as he advanced. At length, 1 saw Experiment 
draw nigh and the columns of the portico of the Temple of Hypotheses 
tremble, its roof cave in, and its floor yawn open beneath our feet. . . . 
it collapsed with a frightful roar, and I woke up. The Sultan s sole com 
ment about this dream, as Louis XV s might well have been, was that it 
had given him a headache. 

People fond of Diderot are inclined to say that passages like these go 


far to redeem the work, and it is well to remember that Andre Gide noted 
in his Journal that he read Lcs Bijoux indiscrets with rapture/ 10 Moreover, 
many people argue, there is something of the scientific in Diderot s treat 
ment of the sexual (and the sexually abnormal) in this novel. As one 
modern critic suggests, even the rather heavy-handed facetiousness of Les 
Bijoux indiscrets indicates an attention, an analyst s and psychologist s in 
terest in the scabrous details of sexual life. n Still, Les Bijoux has had quite 
enough editions, and enough illustrated editions, to prove that it is a 
dirty book. Within a few months of publication, six editions in French 
were printed in Holland alone. 12 In France, the book was highly contraband 
as well as popular: in 1754, for example, the police descended upon a book 
seller and discovered a stock of sixty-four copies. 13 An English translation 
appeared in 1749, and German ones in 1776 and ityi. 1 * The book is still of 
interest to collectors and others: there have been ten editions in France 
since 1920. Lcs Bijoux, in short, is Diderot s most published work. 

There is a school of critics that, when faced with the necessity of saying 
something about an obscene work, tends to take the itVnot-amusing-itV 
just-dull line. Thus Carlyle, in his essay on Diderot, spoke of Diderot s 
writing the beastliest of all past, present or future dull Novels; a difficult 
feat, unhappily not an impossible one ; and the late George Saintsbury 
agreed, in his History of the French Novel that it really would require a 
most unpleasant apprenticeship to scavenging in order to discover a dirtier 
and duller/ 15 Actually, Diderot s work was far from dull Quite to the 
contrary, it was lively lively with ideas, lively with dialogue, lively with 
sallies. It was smutty perhaps, as a French critic believes, the circum 
stances of Diderot s disordered youth had served to dirty his imagination 
16 but it wasn t dull. And the most honest criticism of it would be some 
thing like that which appeared in a recent history of French literature: Its 
verve and keenness do not excuse its obscenity. 17 

Diderot was a little out of his element in writing about a king and his 
mistress, and this evidently was palpable to people of the time who were 
sensitive to social nuances. The Abbe Raynal, reviewing Les Bijoux, called 
the book obscure, poorly written, in a coarse and vulgar tone, and by a 
man ill-acquainted with the milieu he has desired to depict. The author is 
M. Diderot, who has very extensive knowledge and a great deal of wit, but 
who is not suited for the genre in which he has just written. 18 Other con 
temporary criticisms were also adverse, although one of the most hostile 
of all admitted the verve of the work. One cannot deny, wrote this critic, 
that his Bijoux frequently say some very sensible things; but they are 


wrapped up in so many dirty and cynical images and expressions, that their 
utility can never be comparable to the danger to which the most dispas 
sionate mind would be exposed in reading them/ 19 

Years after the publication of Les Bijoux indiscrets, Diderot professed to 
Naigeon that he regretted having written it. He often assured me that if 
he could make good this error by the loss of a finger, he would not hesitate 
to sacrifice it for the sake of suppressing entirely this delirium of his imagina 
tion. 20 Even so, some years after its publication he added two chapters to 
the original edition internal evidence shows that it could not have been 
before 1757 21 and we can believe, along with Diderot s later editor, 
Maurice Tourneux, that if Diderot was willing to sacrifice a finger, it would 
have been the little one, and that on his left hand. 22 

Diderot was, as usual, running risks. It was dangerous to have written 
such a work, yet it was soon an open secret in Paris as to who the author 
was. Nor were the police the last to learn of it. An informer named Bonin, 
a most interesting character who operated a supposedly clandestine press, 
wrote to the Lieutenant-General of Police not later than 29 January 1748 
that Dridot had just given to the public Les Bijoux indiscrets; and on 14 
February of that year the same informant wrote that it is Mr. Durand, 
Rue St. Jacques, who had Les Bijoux indiscrets printed and who sells them. 
He bought the copy from Dridot for 1200 livres. This publisher is very 
worried, as are also Messrs. David and Briasson, who fear that something 
might happen to Dridrot that would suspend the Dictionary of Medicine 
of which Dridrot is editor. 23 

Diderot, moreover, increased the risks he was already running by having 
a hand in the preparation of a fairy story called L Oiseau blanc, conte bleu 
( The White Bird ), a conte bleu signifying a sort of unbelievable, fabulous 
tale. 24 The White Bird was patently inspired by the Arabian Nights: a 
sultana, finding it difficult to go to sleep, has this story told to her during a 
succession of seven nights, with infallible soporific effect. It is likely to have 
that effect on the reader too, for The White Bird, which recounts the ad 
ventures of Genistan, the son of the Emperor of Japan, whom a wizard had 
metamorphosed into a pigeon and who regained his pristine state only after 
being touched by the wand of the fairy Truth, is a mawkish and insipid 
tale even though it did receive the honor of a German translation in 1907. 
Presumably it was written as a sequel to Les Bijoux indiscrets, for it re- 
introduces some of the characters from that book, but it has none of the bite 
and none of the social comment that distinguished Les Bijoux. There are 
some commonplaces about truth and how truth does not customarily reside 


at courts, but these mild platitudes are far from the questing fierceness with 
which the mind of Diderot usually pursued truth, seeking her in the sci 
entific and methodological developments of his time. Indeed, the contrast 
between this tale and anything else Diderot ever wrote is enough to raise 
the question of whether he really did write it. He himself emphatically dis 
owned it. Then, under pressure, he added, It is by a lady whom I might 
name, since she herself doesn t conceal it. If I have any part in this work, 
it is rather in having corrected its orthography, against which ladies with 
the greatest intelligence are always somewhat at fault/ 25 Yet Naigeon, in 
spite of this testimony, published L Oiseau blanc in his edition of Diderot s 
works appearing in 1798, the first publication of the tale. Naigeon, whom 
Diderot had appointed as his literary executor, was certainly in a position 
to know. Consequently, critics have accepted L Oiseau blanc as being from 
the hand of Diderot, or at least greatly affected by him. 26 

The White Bird is really composed of very uninflammable stuff. But 
evidently rumors were rife about it at the time, for the police, under the 
impression that it contained derisive allusions to the King and Mme de 
Pompadour, tried hard to track it down. Considering its literary merits, all 
that can be said is that this official perturbation complimented the work a 
good deal more than it deserved. 

Les Bijoux indiscrets was the sort of book that might seriously impair a 
man s scholarly reputation. What was even worse, Diderot did not yet have 
much of one to destroy. By his own confession, he hoped that his Memoires 
sur different sujets de mathematiques, on which he was working in early 
1748, would prove to the public that I was not entirely unworthy of the 
choice of the associated publishers [of the Encyclopedic]. 27 At the same time 
he had undertaken a translation of Joseph Bingham s monumental Origines 
ecclesiasticae, or the Antiquities of the Christian Church, a translation which 
certainly was never published and possibly never completed. 28 It is probable, 
however, that Diderot put his knowledge of Bingham to good account in 
the Encyclopedic, especially in view of the fact that both works are well- 
informed about the multitudinous heresies of the Christian Church. Also 
in 1748 Diderot was persistently reported to be working on a History 
of the Expeditions of England, but this rumor was evidently erroneous, for 
the French edition of Thomas Lediard s Naval History of England, pub 
lished eventually at Lyon in 1751, was the translation, by all accounts, not of 
Diderot, but of De Puisieux, the husband of Diderot s mistress. 29 

Of greater importance in this year of varied intellectual activity was 
the fact, asserted by Diderot in his 1749 statement to the police, that 1 have 


done the Exposition du systime de musique de M. Rameau! 30 This inter 
esting remark for Rameau was the most significant French composer of 
the eighteenth century, the discoverer* of thorough-bass, and a musician 
whose music still has both freshness and body has set bibliographers won 
dering as to just which work was meant. Raynal, reviewing Diderot s 
Memoirs on Mathematics, remarked that Diderot was f an intimate friend 
of M. Rameau, whose discoveries he is presently going to publish. This 
sublime and profound musician published formerly some works in which 
he did not include sufficient clarity and elegance. M. Diderot will rework 
these ideas, and he is most capable of setting them forth to excellent ad 
vantage. Sometime later the same journalist remarked: Our very illustrious 
and celebrated musician, M. Rameau, claims to have discovered the prin 
ciple of harmony. M. Diderot has lent him his pen in order to set forth this 
important discovery to its best advantage. 31 Perhaps this work was Rameau s 
Demonstration du principe de I harmonie (Paris, 1750), and indeed the 
evidence seems to suggest that it was. D Hemery, the police inspector who 
confiscated La Promenade du sceptique, entered in his journal for 17 Feb 
ruary 1752 that the Siemens de musique theorique et pratique suivant les 
principes de M. Rameau was done by Diderot. 32 This work, however, was 
always claimed by D Alembert, and it is probable that in this instance 
D Hemery was mistaken. It is certain, however, that the versatile Diderot 
was, in some ghost-writing way, associated with the greatest French musician 
of the century, an association which incidentally had a great cooling-off when 
Rameau began to attack Rousseau s articles on music in the Encyclopedic ?* 

Diderot s Memoir es sur differ ens sujets de mathematiques was published 
by Pissot and Durand, the latter being the Durand of the publishers of the 
Encyclopedic, and was brought out in a format de luxe, with six delightful 
engravings, as, for example, cupids tracing # s on a sheet of paper, or fixing 
pegs in the cylinder of a mechanical organ, so that, as Tourneux remarked, 
the volume is one of the most coquettish that was ever published on such 
arid subjects/ 34 Diderot wrote in his signed dedication to a Mme de 
P * * * probably Mme de Premontval, a mathematician and the wife of 
a mathematician, and not Mme de Puisieux 35 I am giving up the cap and 
bells, never to take them up again. 1 

The five mathematical papers were summarized by Diderot as follows : L 
The general principles of the science of sound, with a special method of 
fixing the pitch, in such a manner that one may play a piece of music on 
exactly the same pitch at whatsoever time or place; II. A new compass made 
of the circle and its involute, with some of its uses; III. Examination of a 


principle of mechanics concerning the tension of cords . . . ; IV. Project 
for a new organ . . . [this was the article that had been published anony 
mously in the Mercure de France the preceding year]; V. A letter on the 
resistance of the atmosphere to the movement of pendulums, with an ex 
amination of the theory of Newton on this subject. 

The Mtmoires sur differens sujets de mathematiques received a very good 
press. The censor to whom the manuscript had been submitted set the tone, 
for he remarked that these papers were treated with great sagacity. 36 
Diderot was beginning to make his mark. M. Diderot (to judge by this 
essay)/ wrote the Journal des Sgavans, is very much in a position to give 
learned solutions to difficulties that require nice and intricate calculation/ 3T 
The Jesuit Journal de Trevoux invited the continuation of such researches 
on the part of a man as clever and able as M. Diderot appears to us to be, 
of whom we should also observe that his style is as elegant, trenchant, and 
unaffected as it is lively and ingenious. 38 And the Mercure de France re 
marked: Here is quite a number of new views in a volume that with its 
table of contents includes not more than 250 pages. The author was already 
known to be a man of a great deal of wit. Upon reading these memoirs, one 
will discover that he adds to this advantage that of also being a learned 
musician, an ingenious mechanician, a profound geometrician/ 39 It is no 
wonder that the Abbe Raynal thought it time to modify his opinion of this 
rising star. In introducing his review of the Memoires sur . . . mathe 
matiques, he began: I don t know whether you have heard of a M. Diderot, 
who has a good deal of wit and very extensive knowledge. He has made 
himself known by his writings, most of them imperfect, yet filled with 
erudition and genius, 40 

A recent and authoritative article on Diderot as a mathematician con 
cludes that by this series of papers he proved himself competent and original. 
Moreover, he also demonstrated himself to be conversant with the current 
developments in the field, especially the works of Euler and D Alembert. 
He was well grounded in the earlier mathematical literature, judging from 
his acquaintance with the ideas of Pythagoras, Aristoxenes, Gassendi, Halley 
and Flamsteed, Newton and others referred to in his Memoires!* 1 And 
Julian Coolidge remarked, C I cannot leave Diderot without expressing my 
admiration for his really stimulating mathematical work, when his other 
interests were so large and so varied. 42 

We might well suppose that by this volume Diderot had proved once for 
all his mathematical competence. Yet by a strange twist of fortune he has 
become known to a large part of the English-reading public as a mathe- 


matical dunce. Some twenty-five years after Diderot had published these 
mathematical papers, a story circulated around Berlin about a practical joke 
that may (or may not) have been played upon him during his visit to Saint 
Petersburg. According to this story, a Russian philosopher offered to prove 
to Diderot algebraically the existence of God. So, in the presence of the 
Court and with the secret acquiescence of the Empress, the story goes, the 
Russian philosopher gravely approached Diderot and said in a tone ringing 

a 4- b n 

with conviction, Sir, i=x. Therefore God exists. Reply. The point 

of this story, as originally told, was that Diderot, momentarily casting about 
for the most effective reply to the ineptitude of this alleged proof, sensed 
from the attitude of the courtiers that a joke was being played upon him 
and that all those present were in on it. The Berlin source did not include 
Diderot s reply, but it did state that this misadventure caused Diderot to 
apprehend that others might be in store and convinced him that the intel 
lectual climate of Russia was not congenial, so that he soon signified his 
desire to return to France. 43 

In the course of time the point of this story became twisted, so that it is 
often told by authors of books on popular mathematics as an illustration 
of the horrible fate that awaits a person ignorant of mathematics. The 
anecdote was published in 1867 and 1872 by an English author, De Morgan, 
with gratuitous additions; first, that the Russian philosopher involved was 
Euler, and second, that algebra was Hebrew to Diderot. 44 Bell, in his Men 
of Mathematics, tells the story as it was twisted by De Morgan, his only 
variation being in the remark that all mathematics was Chinese to Diderot. 45 
And Lancelot Hogben begins his Mathematics for the Million with this 
same dramatic tale, his variant being that algebra was Arabic to Diderot. 46 
How the story has been contorted and has grown to this misshapen state 
has been remarked on by three contemporary scholars, one of whom says, 
in allusion to the De Morgan-Bell-Hogben fabrication, That is the story, 
and it is a very good story, except that it isn t true. 47 

As Diderot went through life, he lost faith in Christian immortality, and 
instead fixed his hopes on the sort that comes from having one s deeds live 
in the memory of posterity. Could he be aware that the rank and file of 
posterity, at least in English-speaking countries, are now likely to remember 
him more for being mathematically illiterate than perhaps for any other 
thing, he might be tempted to hedge his bet. 


Letter on the Blind 

THE French Enlightenment not merely originated 
new ideas : it applied them to existing institutions. 

And eventually, of course, the process burst a good many old bottles. This 
attitude made the philosophes, with Diderot a leader among them, the 
radicals and the unconscious revolutionaries of their day. Indeed, their 
pronounced interest in practical affairs has justly earned for the philosophes 
the reputation of being reformers but at the cost of their reputation as phi 
losophers. Diderot s own progressive outlook and concern with practical 
matters were evidenced at this time by a pamphlet advocating a reform that 
finally was brought about in 1793. This anonymous work, dated 16 Decem 
ber 1748, was entitled First Letter from a Zealous Citizen Who is neither 
a Surgeon nor a Physician, To Monsieur D. M. . . . In which is Proposed 
a Means for Settling the Troubles that for a long Time have Divided Medi 
cine and Surgery. 1 The condition that had aroused Diderot s interest was a 
preposterous though long-standing division of labor in French medicine. 
This practice decreed that in the treatment of patients, physicians might 
not operate and surgeons working on the case might not express an opinion 
that in any way had to do with general or internal medicine. Moreover, the 
physicians considered themselves infinitely superior, socially and intellectually, 
to the surgeons. The origin of this irrational distinction, or what the soci 
ologist is fond of calling the peckingorder, goes back to medieval times, 
when all physicians were clerics. This had the not unnatural tendency, in 
cidentally, of causing them to neglect gynecology and obstetrics, a field 
which was left to the midwives; but what was more to the point, their status 
as clerics forbade their shedding blood. Since they could not perform opera 
tions, this was done by the barber-chirurgeons. Moreover, physicians, com 
ing from the class of bourgeois notables, were forbidden under pain of 



losing their status to exercise for gain any skill requiring the use of hands. 2 
The social results of this sort of snobbery were painfully evident and, as 
is so often the case in jurisdictional disputes, it was the public who suffered 
the most. Against this Diderot inveighed. What are we about? he cried. 
Where is our shame? Where is our humanity? 

Diderot s solution was for both physicians and surgeons to be united in 
the same body under the same name. Aesculapius, Hippocrates, and Galen 
practiced both medicine and surgery, he remarked. Therefore, what disad 
vantage is there today in the same person s ordering and executing a blood 
letting? Let . . . doctors and surgeons form a single corps; let them be 
assembled in the same college, where students may learn the operations of 
surgery and where the speculative principles of the art of healing may be 
explained to them. . . / 8 

The Letter from a Zealous Citizen bespeaks an interest in medicine which 
is not at all surprising in one who had spent so much time and energy in 
translating James s Medicinal Dictionary. This interest remained constant 
with Diderot throughout the years, so that one finds him a close friend of 
the Genevese, Theodore Tronchin, the most famous doctor of his generation 
in all of Europe, and of Theophile de Bordeu (1722-76), a pioneer in the 
study of glands and mucous membrane. Diderot also delighted in the study 
of anatomy, and lost no opportunity, for example, to praise the anatomical 
models devised by a Mile Biheron. 4 Diderot s profoundly thoughtful and 
speculative D Alembert s Dream is based upon a great variety of medical 
and physiological knowledge, and one of his last books was Elements de 
physiologic (1774-80). The fact is, he wrote late in life, it is very difficult 
to think cogently in metaphysics or ethics without being an anatomist, a 
naturalist, a physiologist, and a physician. 5 

Even in the wording of its title, the Letter from a Zealous Citizen betokens 
the changing social values of an age beginning to be on the march. The 
eighteenth century was commencing to emphasize the concept of belonging, 
of citizenship. Diderot was among the leaders of this movement, and the 
term citoyeri appears very frequently in the pages of the Encyclopedic. 
Destined by the time of 93 to bear pungent and sometimes bitter fruit, 
citizen was one of the pleasant and slightly radical words of the eighteenth 
century. Thus we have Diderot ending his letter with a fine humanistic 
flourish: I am a good citizen, and everything that concerns the welfare of 
society and the life of my fellow men is very interesting to me. 6 

Problems of citizenship, it so happened, were being canvassed rather 
generally in France in 1749, for this was a year of hunger and distress, 


accompanied by a considerable ferment of opposition to the government. 7 
In part the unrest was caused by discontent with the Treaty of Aix-la- 
Chapelle, which had recently brought to an end the War of the Austrian 
Succession and which, said the captious, was the peace that passeth all 
understanding. There was also disquiet owing to the opposition of the privi 
leged classes, especially the clergy, to the imposition of a tax called the 
vingtieme, promulgated in May of 1749, which would have had the effect 
of introducing into the French governmental system the principle of the 
obligation of everyone to pay proportionate taxes. 8 The attempt to enforce 
this simplest sort of elementary fairness in the incidence of taxation was 
bitterly resisted and obstructed by the privileged classes, whose previous 
connections with public finance had been more on the receiving than the 

paying end. 

In retrospect, 1749 seems a crucial year in the history of the eighteenth 
century and the annals of the French monarchy, in part because of what 
happened to Diderot and Rousseau within that twelvemonth. No doubt to 
a person taking the auspices at that particular moment, only the faintest 
hint of thunder could be heard on the left. Yet the intellectual climate of 
opinion experienced a new pressure front that very year. A nineteenth- 
century editor of Barbier s Journal, a major source for the history of France 
in the eighteenth century, remarked that the year 1749 is a remarkable 
date in the literary history of the eighteenth century. It is at this date that 
writings hostile to religion appear and multiply. . . . Henceforth war breaks 
out between skepticism and faith. Barbier, who up to this point has spoken 
only of ballad writers and poets, now speaks of the philosophes. It is at 
this point that the real eighteenth century begins. 9 

Seventeen hundred forty-nine was a year of transition in France. It marked 
the epoch when intellectual prestige was transferring its headquarters to 
a new field, while subjects hitherto regarded as almost untouchable mysteries 
began to be matters for critical comment. The crucial nature of this year 
was observed by a French historian, Rulhiere, even before the Revolution. 
Being welcomed into the French Academy in 1787, Rulhiere mentioned in 
his formal discourse that the year 1749 was the one in which a general revolu 
tion in manners and in letters began. In that very year in which were pro 
duced all these great philosophical works, we saw beginning a succession 
of unfortunate events that little by little and from day to day stripped from 
the government that public approbation and esteem that up to that time 
it had enjoyed; and while we passed from the love of belles-lettres to the 
love of philosophy, the nation, owing to a change explained by causes quite 


different, passed over from acclamations to complaints, from songs of tri 
umph to the clamor of perpetual remonstrances, from prosperity to fears 
of a general ruin, and from a respectful silence regarding religion to im 
portunate and deplorable quarrels. . . . The capital [Paris], which for so 
long a time had been the prompt and docile imitator of the sentiments, taste, 
and opinions of the Court, at the same time ceased to have for the latter its 
old-time deference. Then it was that there arose among us what we have 
come to call the empire of public opinion. Men of letters immediately had 
the ambition to be its organs, and almost its arbiters. A more serious pur 
pose diffused itself in intellectual works: the desire to instruct manifested 
itself in them more than the desire to please. The dignity of men of letters, 
a novel but an accurate expression, quickly became an approved expression 
and one in common use. 10 

Manifestations of the growing malaise in the French body politic, first 
identifiable in 1749, were even then interpreted by some as the beginning 
of a revolution. The Marquis d Argenson recorded in his famous journal 
on i May 1751 that people are talking of nothing but the necessity of an 
early revolution because of the bad condition in which the government finds 
itself internally. 1:L It is very much worth remembering that the Encyclopedic 
was being prepared and its first volumes published against this background 
of confused and muted discontent. 

In contrast, Diderot s personal affairs seemed prosperous. In 1748 and 
1749 he continued to receive regularly his monthly stipend of 144 livres. 
To this could be added the 1200 livres he is known to have received for Les 
Bijoux indiscrets, and he may have received something for Memoires sur 
di-fferens sujets de mathematiques, though of this there is no record. The 
added security of his financial position was reflected in his moving his 
family from the Rue Mouffetard to a third-floor apartment in a building, 
built in 1681 and still standing, at 3 Rue de TEstrapade. 12 Perhaps, one thinks 
as one ascends the stairs, Diderot walked up and down these steps and slid 
his hand along this very stair rail. Perhaps it was at this very landing that 
Mme Diderot assaulted the neighbor s servant girl. Or, observing the house 
from across the street, one gazes at the very window from which Diderot s 
wife, perhaps with her three-year-old son at her side, looked down to see 
her husband carried away by the police. 13 

Diderot, although he was not now living quite so surreptitiously, was still 
keeping his marriage a secret from his relatives at Langres, and that may 
have been the reason why he seems to have made no effort to go home at the 
time of his mother s death in October 1748. He inherited some property 


from her estate, but just how much or when it became available is not 

known. 14 

During these months the Encyclopedic, of course, continued to be in 
active preparation, and Diderot, besides writing manuscripts to enhance his 
reputation as a savant (such, for example, as the forthcoming Letter on the 
Blind], was occupied with all the organizing, directing, persuading, and 
exhorting that his position entailed. Probably he made it a point to pay 
somewhat ceremonious visits to important contributors, i we may judge 
from an incident in 1751 when the Chevalier de Jaucourt proposed to call 
upon Diderot in order to volunteer his services. 1 shall be charmed indeed 
to have the honor of seeing you at my house, wrote Diderot, but allow me 
to pay you a visit. 15 No doubt Diderot went the rounds on errands like 
this in 1748, if his being reimbursed on several occasions for cab fare is any 
indication. 16 In addition he made extensive use of the Royal Library, now 
called the Bibliotheque Nationale, and on occasion was granted the unusual 
privilege of borrowing books from it. In his prospectus for the Encyclopedic, 
Diderot acknowledged the invaluable assistance of the Royal Librarian, and 
the registers in which are recorded his numerous withdrawals still exist. 17 
The work on the Encyclopedic was going on apace, but, as the publishers 
of the venture were soon to learn, all came to a stop if Diderot was not there. 

Seventeen hundred forty-nine was a memorable year in the life of Diderot. 
And so it was to many others. To the let- em-eat-cake segments of society 
it was noteworthy for the first appearance of a live rhinoceros in Paris. To 
transport him on land, a covered wagon, drawn sometimes by twenty horses, 
has been used. He eats up to sixty pounds of hay and twenty pounds of 
bread a day, and drinks fourteen pails of water. He eats everything but meat 
and fish/ reported Raynal in his news letter. And then he added, It ap 
pears that so far rhinoceroses have not been very useful. 1S To other elements 
of society, especially authors, 1749 came to mean a year selected by the 
government to attempt by confiscations, arrests, and imprisonments to dis 
courage the expression of radical ideas. 19 D Argenson remarked in August 
that because of the great number of such arrests the Paris prisons were so 
full that some of the culprits had to be sent to Vincennes and other outlying 
prisons. 20 And it was just this year that Diderot chose for the publication 
of an extremely original, controversial, and dangerous book. 

This work, Lettre sur les aveugles h V usage de ceux qui voient ( Letter 
on the Blind for the Use of Those Who See ), combined a great deal of sci 
entific observation with some very upsetting metaphysical speculation. It 
was printed clandestinely by a printer named Simon; was sold under the 


counter, of course by Durand, one o the four publishers of the Ency 
clopedic; and was published or, at least, was ready for bootlegging on 
9 June I749- 21 The book greatly enhanced Diderot s reputation as a man of 
letters and a learned person, as the very fact of Voltaire s letter to him in 
acknowledgment of a presentation copy amply signifies; but its publication 
was also the occasion for a frightening experience which evidently chastened 
him a good deal. The appearance of the Letter on the Blind, therefore, 
ushered in a period of major crisis in the life of a man who could not keep 
himself from continually meditating on new ideas. 

The particular occasion for the book, which had to do with the psychology 
of blind people and with what must be the ethical ideas of a person deprived 
of one of his senses, was an operation performed in Paris to restore sight. 
News had gotten about that a Prussian oculist, sponsored by the well-known 
French scientist Reaumur he of the thermometer, and the man who first 
worked out the technique of the artificial incubation of eggs was going 
to couch the cataracts of a girl born blind. Diderot claimed that he and 
many others with scientific interest in the case had asked to be present when 
the bandage was taken off the girl s eyes so that they might observe her at 
the moment when she was first able to see objects. But Reaumur had re 
fused such requests: In a word, wrote Diderot, he has not wished to let 
the veil fall except in the presence of some eyes of no importance/ 22 The 
eyes of no importance, according to Mme de Vandeul, were those belonging 
to Mme Dupre de Saint-Maur, the wife of an obscure writer who owed his 
seat in the French Academy either to his translation of Paradise Lost (1729) 
or to certain connections formed by his wife no one seemed to be quite 
sure which. This lady was on very friendly terms not only with Reaumur 
but also with Count d Argenson, the Secretary of State for War who, since 
1737, had been the Director of Publications. It may have been, therefore, 
that personal reasons, as well as reasons of state, accounted for Diderot s 
arrest. 23 It is certain that Diderot s relations with Reaumur from then on 
were unsettled and at length became antagonistic. 

The Letter on the Blind is a disarming book, written with the seeming 
artlessness of someone idly improvising on a musical instrument.* One 
subject suggests another, so that the reader, led on and on through a sort of 
steeplechase over most of the various metaphysical jumps, finally gets him 
self soaked in the water hole called Does God Exist? The work begins 
with a number of acute firsthand observations of the behavior of a man 

An English translation is in Margaret Jourdain, Diderot s Early Philosophical Worlds (Chi 
cago, 1916), 68-142. 


born blind, a man of considerable intelligence whom Diderot knew per 
sonally. In addition, Diderot used supplementary information about the 
behavior of the blind, and especially about the acuteness of their senses of 
hearing and touch, which he found in the introduction to Nicholas Saunder- 
son s Elements of Algebra. Saunderson, blind from birth, had been a famous 
Cambridge professor of mathematics, his particular specialty being, of all 
things, optics. To help himself in imagining geometrical problems and in 
making computations, he had devised a sort of arithmetical and geometrical 
abacus, a palpable arithmetic/ as the title of his book described it. After 
explaining the operation of this device, Diderot began to speculate upon 
the kind of concepts of God and of right and wrong that a person must 
have who has less than the normal number of senses. This was an original 
way of thinking about such matters, for it clearly suggested that our ideas 
about God and morality are not absolute but relative to our physical make-up 
and endowment. No wonder that some people sniffed materialism in this 
point of view, especially as Diderot invented what purported to be a veridical 
account of Saunderson s death-bed conversation in which the professor was 
made to declare that If you want me to believe in God, you must make me 
touch Him. 24 

By this method of thinking, Diderot was experimenting with a type of 
investigation that has since been very successfully developed in medicine, 
biology, and psychology. It is the method of trying to find out about the 
nature of the normal by studying the abnormal, of learning about the nature 
of the well through studying the diseased. It was always characteristic of 
Diderot to study the pathology and teratology of a subject in order the 
better to understand its normalities. And because this line of thought led 
him to meditate on monsters and how their malformations make them 
unfitted to survive, he began to speculate about the emergence and modifica 
tion of biological species in a way that clearly foreshadows Darwinism. 25 

The last third of the Letter on the Blind speculates on the famous question 
propounded by William Molyneux (1656-98) : suppose a blind man, in the 
instant of recovering his sight, to see a cube and a sphere resting on a table. 
Would he be able to distinguish the cube from the sphere by sight, without 
touching them? This brain-cracker, fundamentally similar to problems in 
perception that are still puzzling psychologists, deeply concerned the phi 
losophers of the eighteenth century because the answer to it would throw 
light upon such fundamental topics as how human beings think and how 
they know what they know. 26 It was in the hope of securing some light 


on the Molyneux problem that Diderot had wished to be present when 
Reaumur had the bandage taken off the girl with the cataracts. 

The Letter on the Blind, which was addressed to a lady, perhaps Mmc 
de Puisieux, reveals some interesting characteristics of its author. First, of 
course, there was that nimbus of the personal and intimate that characterizes 
so much of Diderot s writing, even the most scientific, and which frequently 
invades the columns of the Encyclopedic, where one might suppose all to 
be impersonal and austere. In the ILetter, too, Diderot s notorious fondness 
for straying from the highroad of his theme and picking sweetly scented 
but somewhat irrelevant nosegays is strongly marked : There we are, a long 
way from our blind people, you ll say; but you must have the goodness, 
Madame, to forgive me all these digressions: I have promised you a con 
versation, and I cannot keep my word without this indulgence. 27 

More importantly, the "Letter on the Blind shows Diderot to be a con 
siderable scientist: in his knowledge of the previous literature of the subject, 
in the accuracy of his observations, as well as in the wealth of his hypotheses 
concerning what these observations might mean. His work shows, for 
example, that he was familiar with Descartes Dioptrics, the writings of 
Bishop Berkeley and of Condillac, Voltaire s Elements of Newton s Phi 
losophy, and Saunderson s Elements of Algebra, a book not translated into 
French until 1756. 

It is impressive, too, to observe how seriously Diderot s observations on 
the psychology of the blind have been taken by scientists and professional 
workers in that field. One of the curiosities in the Boston Public Library 
is a translation of Diderot s work, made by Samuel Gridley Howe and 
printed in raised letters at the Perkins Institution for the Blind in 1857. 
The preface remarks that the work abounds with beauties which they [the 
blind] can keenly relish, & with valuable suggestions by which they may 
profit. In particular, as Dr. Gabriel Farrell, the present director of the 
Perkins Institution, has said: Diderot seems to have been first to call the 
attention of the scientific world to the superior sensory capacities of the 
blind. 28 And the late Pierre Villey, a blind professor of literature at the 
University of Caen, although he contested Diderot s principal thesis, namely 
that a blind man s intellect, personality, and ethical notions are different 
from those of a man with sight, nevertheless acknowledged that Diderot 
had foreseen the proper treatment for a Helen Keller, had evinced a remark 
able taste for psychological observation, and was completely a pioneer in 
his speculations upon the psychology of the blind. 29 


No doubt one of Diderot s intentions in publishing the Letter on the 
Blind was to display his qualifications for being editor of the forthcoming 
Encyclopedic. By this time it was generally known that he was to have an 
important connection with the publication, even though the formal pros 
pectus was not to be circulated for over a year. The Journal de Trevoux 
of April 1749, for instance, alluded to his preparing the Universal Dictionary 
of the Arts and Sciences. 30 Certainly the Letter on the Blind disclosed to 
the public what he could do and on what platform he stood. It revealed as 
the cornerstone of Diderot s manner of thought his assumption, based on 
the writings of John Locke, that the only thing the mind has to work with 
is the evidence conveyed to it by the senses. Put the other way around, this 
doctrine asserted that the mind does not have born within it any notions of 
morality or religion, but simply builds up these concepts upon the evidence 
communicated to it by the senses. This constant and exclusive reference 
to the teachings of experience became the foundation stone for the psycho 
logical doctrine known as sensationalism. These views of Locke had first 
gained circulation in France through Voltaire, who cited them approvingly 
in his controversial and widely read Lettres philosophiques (1734)- By mid- 
century they had become the official epistemology, so to speak, of the 
emerging school of philosophes. From the very first page of the Encyclo- 
ptdic, from the very first words of D Alembert s Preliminary Discourse, 
which is rightly regarded as one of the monuments of the intellectual 
history of man, this point of view is taken for granted. This was the basis 
of the scientific and critical spirit that characterized the Encyclopedic and 
made it the engine for transmuting the values of a whole society. For this 
doctrine, as we explore its implications in problems like the nature of 
being, the nature of reality, the nature of knowing, and the nature of God, 
is extremely corrosive and dissolvent to any religious authority based simply 
upon revelation and to any political authority based simply upon pre 
scription. To those writers who wanted to rally around such a battle 
standard, Diderot s Letter on the Blind served as a recruiting placard: 
Sign up with me! And it is perhaps this quality that accounts for the 
three editions of Letter on the Blind appearing in 1749, and for its receiving 
the flattering attention of Voltaire. 31 

Besides seeking to persuade people to have faith in his intellectual com 
petence, the Letter on the Blind was a personal document constituting a 
further step in the development of Diderot s philosophical thought. Starting 
from the mildly theistic footnotes to his translation of Shaftesbury, written 
most probably in 1744, Diderot had come, in the course of five years, through 


the way stations of deism (the Philosophical Thoughts and On the Suf 
ficiency of Natural Religion), and then of skepticism (La Promenade du 
sceptique), until by 1749 ^ e ^zd reached a pretty thoroughly materialistic 
position: If you want me to believe in God, you must make me touch Him! 
All this had been accomplished at a fairly mature age, between thirty-one 
and thirty-six, and it was done in a spirit that could be described as more 
proscientific than antireligious. There was nothing hysterical or frenetic in 
Diderot s casting off his belief in orthodox Christianity and then his belief 
in any God at all. On the contrary, his attitude had been rather like that of 
a man who, without alacrity and without regret, simply discards tools that 
he no longer regards as capable of doing the job. 

The Letter on the Blind was the occasion for putting Diderot into touch 
for the first time with Voltaire. The latter, evidently having received an 
advance copy of the book, replied at length in a letter dated simply June. 32 
Voltaire, who by conviction was a deist and who, moreover, thought that 
he would have his throat cut if his servants ever came to believe that there 
is no God, expostulated with Diderot on the tendency of his argument toward 
atheism. It was a skillful letter, written by the master whose flattery was so 
exquisite and so appetizing that, as Lord Macaulay said, It was only from 
his hand that so much sugar could be swallowed without making the 
swallower sick. And he ended by inviting Diderot to come to see him and 
partake of a philosophical repast. 

It was a heady invitation, and Diderot replied that the moment of receiving 
Voltaire s letter was one of the sweetest of his life. Still, he did not go. There 
is in his reply a certain standofEshness which his relations with Voltaire 
constantly exhibited until the latter s death in 1778. Through the years it 
was usually Voltaire who accepted the burden of initiating a correspondence, 
infrequent as that was, and Diderot who delayed in replying or did not 
reply at all. Probably a stubborn desire to remain completely independent, 
added to the fact that the two men did not see eye to eye on matters of 
philosophical belief, explains why Diderot treated somewhat distantly the 
century s most famous man of letters. 33 

To Voltaire s arguments about a deistic universe, Diderot replied in this 
letter, I believe in God, although I live very happily with atheists. ... It 
is ... very important not to mistake hemlock for parsley; but not at all 
so to believe or not in God. 34 And having disposed of the matter so sum 
marily, Diderot went on to ask Voltaire to accept copies of the Memoirs 
on Different Subjects of Mathematics, one for himself and one for Mme du 
Chatelet, Voltaire s mistress and an excellent mathematician and physicist. 


Diderot referred to this lady with deference and was evidently overawed 
by her mathematical accomplishments. Thus the lives of these two persons 
briefly touched in a year that was to be crucial for both. In six weeks Diderot 
saw closing upon him the gates of a royal prison of which a kinsman of 
Mme du Chatelet happened to be in charge; within three months of Diderot s 
sending her his book, the lady herself was dead, in tragic and grotesque 
childbirth. What shall we do about the child? Voltaire had been asked 
when it was first realized that Mme du Chatelet, through a liaison with 
the poet Saint-Lambert, was pregnant. Don t let that trouble you, said 
Voltaire airily. We shall give the child a place among Madame du Chatelet s 
miscellaneous works. 35 

The portion of Diderot s letter referring to Mme du Chatelet has only 
recently been discovered. In this same overlooked portion Diderot excuses 
himself from meeting with Voltaire because of exhaustion and because of 
tensions in his private life. O Philosophy, Philosophy! what good are you 
if you do not blunt either the pricks of grief and of vexations or the sting 
of the passions? 36 No doubt he was somewhat exaggerating, in order to 
make his excuses more plausible; but nevertheless his allusions to overwork, 
family dissension, and enslavement to Mme de Puisieux throw interesting 
light on Diderot s condition and state of mind in early June of 1749. 


Diderot in Prison 

A 1 , 

SEVEN-THIRTY in the morning of Thursday, 24 
July 1749, two police officers climbed the stairs of 
the house in the Rue de 1 Estrapade. One of them was D Hemery, the man 
who had previously searched for the manuscript of La Promenade du 
sceptique. He and his companion, a man named Rochebrune, were ad 
mitted by Diderot to his apartment and began to search for any manuscripts 
contrary to Religion, the State, or morals/ It is possible, some authorities 
think, that Diderot may have expected such a visitation, for the police found 
nothing but twenty-one pasteboard cases containing manuscripts that they 
thought pertained to Chambers Cyclopaedia. On a large table serving as 
a desk were found more manuscripts concerning the same work, and two 
copies of the Letter on the Blind. In the presence of the said Diderot, re 
ported the police, we continued our search in the other rooms, and having 
opened the wardrobes and chests of drawers, found no papers therein. 1 
This testimony of Commissioner Rochebrune incidentally affords some 
insight into the conditions of Diderot s daily work, suggesting that he did 
much of his writing at home, f on a large table serving as a desk. This 
routine, however, was about to be suddenly and completely altered, for 
D Hemery told Diderot that he was under arrest. 

It was by virtue of one of the notorious writs known as lettres de cachet 
that Diderot was arrested and imprisoned. Lettres de cachet have become 
one of the most odious symbols of the ancien regime, as every reader of A 
Tale of Two Cities can gauge by consulting his own feelings. Though 
numerous the leading modern historian of Jansenism asserts that forty 
thousand were issued in the seventeen years of Cardinal Fleury s administra 
tion alone 2 perhaps the lettres de cachet were not in reality so abusive 
as they came to seem. Apologists for the good old days point out that for 
the most part they were used to straighten out family tangles, just as Father 



Diderot had secured one in 1742 in order to cool off his hot-headed son, or 
to enforce with contempt-of-court penalties what might be called injunctions 
in cases of private morality. Such apologists also emphasize that there is no 
evidence that these arrest warrants were issued in blank except under very 
carefully controlled conditions, so that the writs never became, as is often 
darkly suspected, the legal instruments of unjust vengefulness. There is no 
record of active maltreatment of persons detained by lettres de cachet: 
no evidence, for example, of torture or starvation, though there is of forget- 
fulness. Indeed, orders were given that people should be granted food and 
treatment in approximate accordance with their social rank. Diderot, for 
example, was to receive the equivalent of four livres a day for nourriture et 
attentions! 3 Finally, a lettre de cachet had to bear the countersignature of 
one of the king s principal ministers, and in this respect unquestionably 
satisfied the forms as much as could be expected of a warrant for arrest in 
any country at any time. 4 

But lettrss de cachet were much less satisfactory in that they did not have 
to state the cause for arrest. Furthermore, persons thus arrested were held 
incommunicado, and it was entirely legal to detain them indefinitely, which 
was of course a frightening and demoralizing prospect. There came to be 
a rather widespread feeling in France while Sartine was Lieutenant-General 
of Police (1759-74) that the practice of issuing lettres de cachet was be 
coming too extensive; 5 by the time of the Revolution, they had aroused a 
great sense of injustice. Perhaps lettres de cachet would not have come to 
seem so great an abuse had they not been the government s favorite method 
of attempting to discipline men of letters. 6 At first this policy was able to 
enforce an apparent conformity; but eventually it boomeranged, winning 
for the monarchy the persistent ill-will of the most articulate element of 
French society. 

Two days before Diderot s arrest, Count d Argenson, acting in his capacity 
of director of publications, wrote to the Lieutenant-General of Police, *to 
give orders for putting Mr. Didrot, author of the book on the Blind Man, 
in Vincennes. Berryer made the order the occasion for instructing his men 
to find out from Diderot all they could about Letter on the Blind, Pensees 
philosophiques, Les Bijoux indiscrets, a work called L AlUe des idtes (prob 
ably La Promenade du sceptique), and LOiseau blanc, conte bleu? On 
23 July the lettre de cachet, countersigned by D Argenson, was made out at 
Compiegne. 8 And on 24 July Diderot and D Hemery made the cab journey, 
at the king s expense, to Vincennes, an imposing medieval fortress and 
former royal residence six miles east of the heart of Paris. 


Having been turned over to the governor of the place, Francois-Bernard 
du Chatelet, the relative of Voltaire s mistress and a man whose correspond 
ence gives the impression that he was well-intentioned but bumbling, 
Diderot was immediately placed in the central keep, 9 This lofty tower was 
one of the most conspicuous symbols of the grimmer side of the ancien 
regime, the very sight of which, wrote the author of an eighteenth-century 
guide book, causes fear. 10 The edifice has had its most famous and its most 
gracious depiction in one of Fouquet s beautiful miniatures for the Due 
de Berry s Book of Hours. It remains today just as it evidently looked to 
Fouquet in the fifteenth century, when he made his calendar-pictures. 
Diderot s place of confinement, according to tradition, was in the north 
west tournelle of the third floor, the floor directly above the room where 
Prince Hal is said to have died in 1422. Diderot s room was octagonal in 
shape, approximately thirteen feet square and twenty-eight feet high, with 
graceful vaultings, a brick floor, a window looking out toward the chateau s 
entrance gate, and an enormous fireplace, its mantel jutting out about six 
feet above the floor. The room (at least as seen in 1939; it was later closed 
to the public), is light and airy and would not have been too unpleasant in 
the summer season, the time when Diderot was there. It was, in short, a 
suitable place for meditation; but there was always the very- great risk 
that he would be left to meditate infinitely longer than he desired. Every 
day, Mme de Vandeul states, the jailer brought Diderot two candles. But 
he, who got up and went to bed with the sun, had no use for them, and 
after a fortnight s accumulation tried to return them. Keep them, keep 
them, Monsieur! cried the jailer; You have too many of them now but 
they ll come in very handy in the winter ! - 11 

In her distress, Mme Diderot sought an interview with Berryer, who 
adopted the rough and tough approach. Well, Madam, we ve got your hus 
band and he d better talk. You might spare him a lot of trouble and hasten 
his release if you would tell us where his manuscripts are. . . . But his 
wife disclaimed knowing anything at all about Diderot s works, claiming 
never to have read any of them. 12 As for the publishers, they were much 
given in this emergency to bustling about in carriages, as their account books 
show. 13 The very day of the arrest the publishers addressed a petition to 
D Argenson in which they stated that the Encyclopedic was on the point 
of being announced to the public and in which they declared that the 
detention of M. Diderot, the only man of letters we know of capable of so 
vast an enterprise and who alone possesses the key of this whole operation, 
can bring about our ruin. 14 


The agitation of the publishers to secure Diderot s release was unre 
mitting all through the time o his imprisonment. Four days after the 
arrest they had presented their case to the Chancellor and had come to the 
conclusion that nothing would be done until the Lieutenant-General of 
Police had interviewed Diderot and reported thereon. Consequently they 
besought Berryer to interrogate the prisoner: he [Diderot] is the center 
where all the parts of the Encyclopedic have to converge; his detention 
suspends all operations on it and will inevitably bring about our ruin if it 
should be at all long. 15 

The interrogation, which took place in the tower, occurred on 31 July, 
exactly a week after the arrest. Apparently Diderot was still hoping that he 
could brazen things out. Already he had persuaded one of the prison officers 
that golden tongue again to present directly to Berryer a request to be 
allowed to use the large central room of the storey in which he was con 
fined, a request evidently annoying to the Marquis du Chatelet, who did not 
care to have his authority thus short-circuited. 16 During the interview with 
Berryer, Diderot admitted nothing. Moreover, he declared under oath that 
he had not written the Letter on the Blind nor caused it to be printed nor 
had he sold or given the manuscript of it to anyone; that he did not know 
the identity of the author, that he had not had the manuscript in his pos 
session either before it was printed or afterward, and that he had not dis 
tributed or given copies of the book to anyone. As for Les Bijoux indiscrete 
and Pensees philosophiques, he swore that he had not written them, and 
he specifically stated that he did not know who was the author of the 
Pensees. He further claimed not to have written or corrected L Oiseau blanc, 
but admitted to having written La Promenade du sceptique, saying that 
the manuscript had been burned. 17 Inasmuch as Berryer learned the very 
next day from the publisher Durand that Diderot was the author of the 
Pensees, the Bijoux, and the Lettre sur les aveugles, the magistrate evidently 
adopted the policy of simply waiting until Diderot saw fit to volunteer more 
information. 18 

Under this sort of duress Diderot began to suffer very much. This was 
natural enough, for the extreme sociability of his nature and his talkative 
ness made him less fitted than most people for the rigors of solitary con 
finement. Though Diderot had been given much more freedom by the 
time Rousseau was allowed to see him, the visitor found Diderot greatly 
affected by his imprisonment. The keep had made a terrible impression 
upon him and, although he was [now] comfortable at the castle and allowed 


to walk where he pleased in a park that was not even surrounded by walls, 
he needed the society of his friends to avoid giving way to melancholy. 19 
Condorcet, a much younger contemporary of Diderot, is reported to have 
said that Diderot almost went crazy while he was in solitary confinement. 20 
This is quite possible, especially in view of Diderot s unusually powerful 
and vivid imagination and sensitivity. His emotional response to situations 

to music, to a generous action, to plays, to pictures, to an act of injustice, 
to anything either aesthetic or ethical that was beautiful or hideous was 
extreme. It is therefore quite possible that there was little exaggeration in 
the long letter that he wrote to Berryer in which he darkly hinted that he 
might do violence to himself. 

This letter of 10 August 1749, in which he states incidentally that my 
father is still ignorant of my marriage, is as characteristic of Diderot as 
anything he ever wrote. It contains the sensibility for which he is famous 

1 feel that despair will soon finish what my bodily infirmities have greatly 
advanced ; the bouquets naively thrown at himself by his own willing hand; 
the torrential and expostulatory style that he made very plausible and con 
vincing whenever he wrote in passionate defense of his own innocence and 
virtue; and a certain deliberate obtuseness in failing to conceive what he 
could possibly have done wrong. And in all this lengthy letter he does not 
say a word about the Pensees, the Bijoux, or the Letter on the Blind! 21 

Writing to D Argenson the same day, Diderot made the same assertions, 
although more briefly and in a more reserved style. But in this emergency 
he had bait to dangle in front of the Secretary of War. Alas! Monseigneur, 
when he [Diderot is here talking of himself] was brought to this prison, he 
was on the point of publishing the prospectus [of the Encyclopedic] and of 
soliciting from Your Highness the permission to publish under your auspices 
this work that has been undertaken for the glory of France and the shame 
of England, and which is perhaps worthy, at least in this respect, of being 
offered to a minister who protects the arts and those who cultivate them. 22 
This proffer was obviously a bribe, a quid fro quo. It is very interesting to 
see that Diderot evidently regarded himself as so exclusively the director 
of the Encyclopedic that he felt free to offer the dedication without first 
consulting D Alembert or the publishers. It may of course be true that he 
really had been intending all along to broach the subject to D Argenson 
and had previously cleared the matter with his associates. But probably 
he had not, for if he had, the publishers would surely have alluded to it 
in their petition to D Argenson. Whether D Alembert knew of it or not 


there is no telling. At all events, when the first volume of the Encyclopedic 
appeared, there was the dedication to D Argenson, the shabby reality making 
the high-flown phrases sound rather brassy and cracked. 

Three days went by and Diderot wrote to Berryer again, on 13 August. 
This time he confessed. After an elaborate beginning, in which he tried to 
ensnare Berryer in the toils of his own generous impulses, Diderot wrote, 
1 therefore avow to you, as my worthy protector, what the tediousness of a 
prison and all imaginable penalties would never have made me say to my 
judge: that the Pcnstcs, the Bijoux, and the Lettre sur Ics aveugles are ex 
cesses that slipped out of me; but that I can on the other hand pledge my 
honor (and I have some) that they will be the last, and that they are the 
only ones. Diderot was evidently in a state of panic, for he even offered to 
reveal the names of the printers and publishers of his illicit works. He 
made this offer, however, contingent upon Berryer s giving his word of 
honor not to use this information in any way whatever to their disadvantage 
unless they were guilty of recidivism. And Diderot, characteristically, offered 
to tell them himself what he had done, if Berryer demanded it. 23 

This confession got results. Sometime before 21 August, Berryer informed 
the Marquis du Chatelet that Diderot was to leave the keep and be allowed 
the freedom of the grounds: His Majesty also saw fit, in view of the editing 
work with which he is charged, to allow him freely to communicate by 
writing or orally in the chateau, with the customary precautions, with per 
sons from the outside who come there either for that purpose or for his 
domestic affairs. . . . You will have the goodness to have assigned to him 
in the chateau one or two commodious rooms for sleeping and working, 
with a bed and such other furniture as you customarily furnish to prisoners 
in the keep, and nothing more, reserving for him to procure greater con 
veniences at his own expense if he desires them. 24 

Berryer wrote out with his own hand the statement that Diderot had 
to sign in order to enjoy these new conditions: 1 promise the Lieutenant- 
General of Police that I will not go beyond the chateau nor its courts nor 
the enclosure of the royal garden nor the bridges [over the moat] during the 
time it shall please His Majesty to have me kept a prisoner, submitting my 
self in case of disobedience on my part regarding the foregoing to be shut 
up all my life in the keep whence it has pleased the clemency of the King 
to have me brought forth. 1 25 

One of the traditions concerning Diderot s imprisonment in the tower is 
that he had to improvise writing materials. An account of this was first 
published in an obscure and rare magazine called La Bigarure, printed at 


The Hague. In its number dated 30 October 1749, Diderot being still in 
prison, La Bigarure told how he used a toothpick for a pen, a mixture o 
wine and pulverized slate for ink, and for paper a copy of Plato, which the 
ignorant jailer had allowed him to keep on the theory that no one could 
get any meaning out of such stuff. 26 Differing versions of the story are told 
by Mme de Vandeul, Naigeon, and Eusebe Salverte, each of whom pre 
sumably got his facts from Diderot himself. 27 Their accounts are fairly well 
reconciled by a document found among the Diderot papers. This is entitled 
Copy of the Notes written on the Margins of a Volume of Milton s Worths 
by M. Diderot during his Detention in the Chateau of Vincennes, these 
notes being The Apology of Socrates, translated from memory. 28 Some 
writing he assuredly did in the tower, whether authorized or unauthorized, 
for he wrote the Marquis du Chatelet in late September to ask whether the 
notebooks that he had filled up there, mostly with notes on BufJon s Natural 
History, might be returned to him. 29 

Because of his demonstrativeness, which always made him very con 
spicuous in whatever situation he found himself, Diderot s release from the 
tower was very likely just the sort of tableau that he admired in the pictures 
of Greuze, genre pictures such as The Village Bride or The Paternal Curse, 
which endeavored to freeze on canvas a sentimental or violently emotional 
scene. For here is the situation, as recounted by Mme de Vandeul: At the 
end of twenty-eight days, my mother was told to go to Vincennes. The 
associated publishers accompanied her [the publishers account book actually 
shows an entry for carriage expenses for this very day, 22 August 1749]. 30 
Upon her arrival, he was brought out of the tower. . . . The imagination 
kindles at the scene: Diderot, very much the center of the picture and 
gesticulating, quite as in real life; his wife, with her back to the beholder 
and in a bad light, as always; the turnkey, with his keys in his hand; perhaps 
the Marquis du Chatelet himself, very elegant in courtly attire; at one side 
the publishers, dressed in sober, bourgeois colors; and, to give variety to the 
scene, no doubt a barking dog or two, come from the Lord knows where. 

Mme de Vandeul went on to describe Diderot s life for the next ten 
weeks. The Marquis du Chatelet heaped kindnesses upon him, invited him 
to his table, and took the greatest care to make this stay as little disagreeable 
and as convenient as possible to my mother. They stayed there three months, 
then they were permitted to go home. 31 Inasmuch as Rousseau says in the 
Confessions that he sometimes accompanied Mme Diderot from Paris to 
Vincennes to visit Diderot, it may be that Mme Diderot did not stay there 
continuously, in spite of Mme de Vandeul s statement that she did. A picture 


of Diderot s routine while in the chateau is also reflected in the Marquis du 
Chatelet s notes to Berryer. One on 30 August required correction and 
amplification, for Berryer replied to it the very next day, evidently in alarm 
lest Diderot was not being held strictly to his word. So Chatelet wrote 
again on 3 September that Diderot had profited only once from the per 
mission to move freely in the courts of the chateau. He has gone out three 
times evenings for an hour with his wife in the park. He is well. Many 
people come to work with him, but I believe he is unable to get much 
done here/ 32 

Into this Eden Lilith came. Mme de Puisieux paid a visit. But Diderot 
had become suspicious of her and finally he slipped out over the walls, 
went to Champigny, saw his mistress there with her new lover, came back, 
and slept in the park. The next morning he went to inform M. du Chatelet 
of his escapade, and this little adventure accelerated his rupture with Mme 
de Puisieux. 33 

It is very hard to know how much of this story to believe. On the one 
hand, a cooling-off in the relations between Diderot and Mme de Puisieux 
did occur at approximately this time. And although it may seem odd that 
Mme de Puisieux should visit Diderot at Vincennes while Mme Diderot 
was there, still Diderot could conceivably have arranged interviews with 
out his wife s knowledge. But it seems unbelievable, considering the penalty 
he might incur, that Diderot would take the fearful risk of breaking his 
parole. Joseph Delort, writing in 1829 with a profusion of underlining^ 
claimed that Diderot afterward asserted (according to the note that lies 
before us) that he went out several times at night to go to see in Paris 
a woman he loved/ 34 M. Delort vouches for this. But who, as Gibbon might 
ask, will vouch for M. Delort? And Funck-Brentano, also without docu 
mentation, declares that the Marquis du Chatelet made these escapades 
possible by conniving at them. 35 Yet, considering the nervousness o Berryer s 
response to what he thought was an indication of laxity in Du Chatelet s 
dealing with Diderot, it does not seem likely that the governor of the prison 
would have been very eager to be accessory to such goings-on. This is the 
sum of the evidence, vague and uncertain as it is. 

Diderot s arrest had caused some public stir and aided a great deal in 
making his name well known. As early as 26 July, an Abbe Trublet wrote 
to a lady of his acquaintance about Diderot s imprisonment: It is this last 
drop of water [Letter on the Blind] that has made the vase overflow, and 
this has come about, it is said, through the complaints lodged by M. de 
Reaumur. You know that he is not well treated in the first few pages. 36 


Voltaire, writing from Luneville, almost two hundred miles from Paris, 
knew of Diderot s imprisonment by 29 July, only five days after it had 
taken place. 37 The entries, not all of them accurate, in the journal of the 
Marquis d Argenson, brother of the Secretary for War, show that the case 
was talked about in ministerial and court circles, just as a similar entry 
in the equally famous journal of the bourgeois, Barbier, proves that Diderot s 
name was becoming known among lawyers at Paris. 38 

Diderot s misfortune had the indirect effect of allowing posterity to know 
who were the persons, and presumably the most influential persons, with 
whom he had any connection in 1749. For in his letters to Berryer and 
D Argenson he mentions as people who could vouch for him, a M. de 
Bombarde (of whom nothing is now known), Voltaire, Mme du Chatelet 
(who had acknowledged his gift of a copy of his book on mathematics), 39 
Fontenelle, Mme du DefEand, Buffon, Daubenton, Clairaut, Duclos, the 
Abbe Sallier, Helvetius, and D Alembert. Many of these came to be great 
names in the eighteenth century, and some were already so. This was true 
of Voltaire and Mme du Chatelet, and especially of Fontenelle, then ninety- 
two years old, the author of the History of Oracles and On the Plurality 
of Worlds, a wonderfully live nonagenarian whom an American sports- 
writer would inevitably have called the grand old man of French letters. 
Mme du Deffand (1697-1780) was the celebrated hostess of one of the eight 
eenth century s most celebrated salons, a lady who maintained her com 
manding intellectual and social position in spite of the blindness that came 
upon her, and who is known to English literature primarily because of her 
interesting and informative correspondence with Horace Walpole. Buffon 
was the famous naturalist, author of the interminable Histoire naturelle, 
the first volume of which appeared in that year, a person much like Samuel 
Johnson in respect to the massiveness and authority of his literary style. His 
colleague Daubenton (1716-99) was also a naturalist, who later contributed 
many articles to the Encyclopedic* Clairaut (1713-65) was an astronomer 
and geometrician whose particular specialty was the movements of the 
moon. Duclos (1704-72) had written a history of Louis XI and had recently 
been elected to the French Academy. The Abbe Sallier (1685-1761) was a 
well-known philologist and custodian of the Royal Library, and Helvetius, 
then the least known of the lot but eventually destined to unenviable 
notoriety as the author of a book entitled De I Esprit, was then a farmer- 
general with an income of some 300,000 livres a year. But if Diderot knew 
these people no better than it can be demonstrated that he knew Voltaire, 
Mme du Chatelet, and Fontenelle > then his acquaintance with them was 


slight indeed. 40 Nevertheless, it is known that Mme du Chatelet wrote to 
her kinsman, the governor of Vincennes, asking him to make Diderot s 
imprisonment as mild as possible, and therefore it is possible that others 
of these persons did what they could in his behalf. 41 

Of one thing Diderot was confident, if we may judge from the prediction 
contained in his letter to Berryer on 10 August: his father would hasten 
to Paris as soon as he learned of his son s arrest. How disconcerting it must 
have been to Diderot, therefore, to find that his father stayed right at Langres 
and would not budge. Diderot s first letter was not even answered. His 
second was replied to on 3 September in a missive of which the spelling 
was frequently phonetic but the meaning unmistakable. Diderot found 
that he was not the prodigal son. The elder Diderot, his letter shows, had 
other sources of information about affairs at Paris than just his son s letters. 
When he wrote, therefore, he wrote with a decidedly detached and astringent 
air, filling his letter with more sense than comfort. He reminded the son 
of his mother, In the remonstrances that she made to you by her own lips, 
she told you several times that you were blind. Didier Diderot s best 
advice, at least in his estimation, was that Denis should straightway write a 
book of Christian edification! This will bring down upon you the bene 
dictions of Heaven and will keep you in my good graces. The father then 
asked whether it was true that his son was married and had two children, 
1 expect that you will not refuse to your sister the pleasure of rearing them, 
nor to me the pleasure of seeing them under my eyes. About money the 
crusty old man became quite sardonic but sent a hundred and fifty livres 
just the same. 42 And probably it was greatly needed in the household in the 
Rue de 1 Estrapade, for the publishers account book shows that Diderot s 
salary was discontinued by them during his imprisonment, there being no 
payment entered between 14 July and late November. 43 

The letters that Diderot had written to his father are not extant. Nor is 
it possible to know what effect the harshness of the letter just quoted had 
upon him. Probably it convinced him that he would have to make his own 
peace with the authorities, and that his liberation was not going to be 
brought about by sentimental arguments or the intercession of relatives. At 
all events, in this same month of September Diderot volunteered in an 
undated note a far-reaching promise as to his future conduct: [he] promises 
to do nothing in the future that might be contrary in the slightest respect 
to religion and good morals. Under this promise, Berryer wrote, If Count 
d Argenson deems that he [Diderot] has done sufficient penance for his 
intellectual excesses, he is entreated to have the King s order sent for his 


release. 44 Berryer s note suggests that Diderot s release depended upon his 
making a solemn promise. If so, it may explain why so many of Diderot s 
subsequent writings were carefully tucked away in a drawer and never 
published during his lifetime. 

None of Diderot s friends was more alarmed or more solicitous in his 
behalf than Rousseau. Nothing can ever describe the anguish that my 
friend s misfortune made me feel. My somber imagination, which always 
expects the worst, took alarm. I thought he would be there the rest of his 
life. I almost lost my mind. When he was first able to see Diderot after 
the release from the tower, Rousseau greeted his friend with embraces, sobs, 
and tears. D Alembert and a stranger were present, and Diderot said to 
the latter, perhaps conceitedly but more likely appreciatively, after the strain 
of three weeks of solitary confinement, You see, Monsieur, how my friends 
love me. 45 

Because of Diderot s imprisonment in Vincennes, the road thither became 
the scene of the most dramatic event of the Enlightenment. The summer 
of 1749 was excessively hot/ wrote Rousseau in his Confessions. It is two 
leagues from Paris to Vincennes. Scarcely able to afford cabs, at two o clock 
in the afternoon I would set out on foot when I was alone, and I walked 
fast in order to get there the sooner. . . . often, quite spent by the heat and by 
fatigue, I would stretch out on the ground able to do no more. In order to go 
more slowly, I decided to take a book. One day I took the Mercure de France 
[the October issue] and as I walked and read, I lit upon the question proposed 
by the Academy of Dijon for its prize for the following year: Whether the 
progress of the sciences and the arts has contributed to corrupting the morals 
or purifying them. At the instant of reading this I saw another universe and 
I became another man. . . . Upon arriving at Vincennes I was in an agita 
tion bordering upon delirium, Diderot perceived it: I told him the cause. 
. . . He exhorted me to give rein to rny ideas and to compete for the prize. 46 

Carlyle in his essay on Diderot suggests the Biblical self-dedication of 
the Encyclopedists when he speaks of the Acts of the French Philosophes, 
a phrase anticipatory of Carl Becker s The Heavenly City of the Eighteenth- 
Century Philosophers. Using such Scriptural comparisons, it may be said 
of Rousseau s revelation that in its suddenness and thoroughness it was 
similar to what happened to Saint Paul on the road to Damascus. Rousseau, 
in a sudden flash of mystical insight, discovered the state of nature, the 
pristine condition of virtue and purity. He saw with blinding certainty that 
the arts and sciences, contrary to usual opinion, had made us worse, not 
better. From then on he was to write books beginning with sentences such 


as "Everything is good as it leaves the hands of the Author of things; every 
thing degenerates in the hands of man (Emile), or Man is born free and 
everywhere he is in chains (The Social Contract). Rousseau threw himself 
into this persuasion of the corruption of society with all the passion of a 
pathologically sensitive person Edmund Burke remarked that Rousseau 
had no skin a person of enormous although unsuspected talents, who 
envies at the same time that he despises a highly sophisticated and polished 
society in which he has not been quite successful. It is the boy from Geneva 
not quite making good in Paris; the African from Tagaste, Augustine by 
name, not quite successful in Rome or Milan. And because Rousseau was 
one of the most eloquent writers who ever lived, his doctrines took on 
enormous political importance in the eighteenth-century movement of ideas. 
For he was dedicated, in brief, to the conviction that whatever is, is wrong. 

As the years went by, Rousseau and Diderot quarreled in a spectacular 
fashion, and Diderot subsequently fell victim to the temptation of asserting 
that it was he who suggested the famous paradox to Rousseau. 47 For ex 
ample, he once told Marmontel at that time a very prominent man of 
letters, though his laurel leaves are now much withered that he had 
asked Rousseau which side of the question he proposed to take. 

"The affirmative," said Rousseau. 

1 "That s the fons asinorum," I said to him. "All the mediocre talents 
will take that path . . ." 

1 "You re right," he said to me, after having reflected upon it for a 
moment, "and Til follow your advice." 4S 

Exactly the same story is told by other contemporaries by La Harpe, 
by Colle, by Meister, and by the Abbe Morellet, who adds that this version 
was accepted as established by all Baron d Holbach s circle. 49 And Mme 
de Vandeul states quite flatly that my father gave to Rousseau the idea of 
his Discourse on the Arts.* 50 Rousseau, on the other hand, solemnly assured 
a friend that he had made his choice without Diderot and solely by himself. 51 
Consequently, as might readily be expected, the question of whether Rous 
seau is to be denied any originality whatsoever has become a favorite battle 
ground for his partisans and his detractors, as well as a focal point for some 
skillful exercises in impartial scholarship. 52 

In his writings, Diderot was much more cautious in his allegations about 
Rousseau and the prize essay. Twice he alluded to the incident, in passages 
one of which was published during his lifetime, the other posthumously. In 
each instance he stops short of declaring that he gave Rousseau the idea; 
he merely takes credit for knowing his Rousseau: 


When the program of the Academy o Dijon appeared, he came to con 
sult me on the side that he should take. 

* "The side you ll take," I said to him, "is the one no one else will." 

"You re right," he replied/ 53 

Although Diderot was now permitted to work on the Encyclopedic, his 
enforced residence at Vincennes was a handicap. As Du Chatelet had re 
marked, he was unable to get much done. The associated publishers, in sup 
port of what they called the finest and most useful enterprise yet undertaken 
by the book trade/ petitioned D Argenson on this subject: 

the enterprise on which Your Highness has deigned to cast some favorable re 
gards cannot be finished so long as M. Diderot is at Vincennes. He is obliged to 
consult a considerable number of craftsmen, who do not like to be shifted about; 
to confer with a number of men of letters, who do not have the leisure to go to 
Vincennes; and finally, to have access constantly to the Royal Library, the books 
of which cannot and ought not to be carried so far away. Besides, My Lord, to 
supervise the drawings and engravings, one must have the workers tools before 
one s eyes, an essential which M. Diderot can make use of only on the spot, 64 

Another and much more elaborate petition dated 7 September covered the 
same ground. 55 

Perhaps the publishers would not have been so importunate had D Alem- 
bert filled in for the absent editor. But evidently he either could not or 
would not; the publishers declared that without Diderot it was impossible 
to instruct the printers how to set up mathematical material correctly. 55 
From this it may be inferred that D Alembert did not concern himself with 
correcting proof, even on material he himself had written, and he seems to 
have taken great care not to contract any guilt by association. At least such 
would seem to be a reasonable interpretation to put upon his letter of 19 
September to Formey, the secretary of the Berlin Academy : The detention 
of M. Diderot has become much less severe; nevertheless it still lasts, and the 
Encyclopedic is suspended. I never intended to have a hand in it except for 
what has to do with mathematics and physical astronomy. I am in a position 
to do only that, and besides I do not intend to condemn myself for ten 
years to the tedium of seven or eight folios/ 57 

In a folder marked Diderot, constituting part of the archives of the 
Bastille that long ago were transferred to the Bibliotheque de 1* Arsenal at 
Paris, there is a little slip of paper addressed to the Marquis du Chatelet 
and written in the hand of Berryer. Dated 29 October 1749, it stated that 
the lettre de cachet ordering Diderot s release had been made out on 21 


October, and that Du Chatelet was to release Diderot as soon as he received 
Berryer s note. Another hand, not Berryer s, scratched out the date 29 
October and inserted instead 3 9 bre> ; and indeed it was on 3 November 
that Diderot was released. 58 

Now he was free to return to the Rue de TEstrapade and to the enormous 
backlog o work that had been accumulating since his arrest 102 days pre 
viously. What were the ideas, the conclusions, that this unwelcome interlude 
caused to revolve in his mind? Many, no doubt, and deep-seated, for the 
atrabilious moods of his solitary imprisonment seem to have darkened his 
thought for several years. Rousseau speaks in his Confessions of the melan 
choly that Diderot acquired during his confinement and asserts that it is 
apparent in Le Fils naturel, written seven years later, 59 But of one thought 
in Diderot s mind we may be sure. Many years later he proposed to Cath 
erine II of Russia that he edit, at her expense, a new and better Encyclopedic: 
one of the advantages would be to substitute the name of a great and worthy 
sovereign for that of a second-rate minister who deprived me of my liberty 
in order to wring from me a tribute to which he could not lay claim by 
merit/ 60 


The Prospectus of the Encyclopedic, 
and Letter on the Deaf and Dumb 

T is more than likely that Diderot spent the last 
weeks of 1749 and the first months of 1750 in seeking 
to make up for lost time. As the publishers second petition to D Argenson 
had gone to great lengths to establish, Diderot was indispensable. 1 The 
preparation for publishing the Encyclopedic could not be carried on satis 
factorily without him. Their statement conveys to us a precise notion of 
how complex a job it was to be chief editor of the Encyclopedic, entailing 
as it did duties requiring not only the conventional blue-penciling and proof 
reading, but also a great deal of what is now called leg-work and tech 
nological know-how. 5 For over twenty years Diderot spent the greater part 
of his time and energy in just this sort of daily editorial work. His was a 
task demanding the combined qualities of the genius and the drudge. 

In the year following his detention in Vincennes there continued to be 
reverberations of the publication of Letter on the Blind. Speaking to the 
quinquennial Assembly of the Clergy, the Archbishop of Sens denounced 
the current manifestations of irreligion, as a result of which that body re 
quested the Sorbonne to make a report on impious books, among them 
Philosophical Thoughts and Letter on the Blind? The fictitious deathbed 
conversation of Saunderson, invented by Diderot, called into being an equally 
fictitious one in reply. 3 Though the principal French periodicals, such as 
the Journal des Sfavans and the Journal de Trevoux, did not deign to notice 
a volume that was, after all, highly contraband, the Letter on the Blind 
received a flattering amount of attention in news letters and periodicals 
published outside the boundaries of France. This book/ wrote one editor, 
has caused too much stir not to devote an article to it here. 4 The stir was, 
indeed, so great that demand far outran supply. D Alembert, writing to a 



friend in Switzerland who had asked for a copy, declared in February 1750 
that it was very hard to procure one. 5 

The year 1750 witnessed a number of important events in the private life 
of Diderot. Not least remarkable among them was a complaint against his 
wife lodged with the police on 2 April. This document is still in existence 
in the National Archives of France, a single quarto sheet rather hard to find 
as it lies unbound and higgledy-piggledy with scores of similar depositions 
in a cardboard box. 6 In this complaint the servant of one of Mme Diderot s 
neighbors testified that on that very afternoon Mme Diderot, after picking 
a quarrel, had kicked the servant several times and knocked her head 
violently against the wall. Nevertheless, the record bears no evidence that 
the authorities did more than simply file the deposition. Apparently Mme 
Diderot was not admonished or even interrogated. Yet the existence of this 
document may surely be cited as proof that Mme Diderot was indeed a 
formidable woman, and that there may have been some basis in fact for 
a report of a similar and equally violent incident involving Mme Diderot 
a year and a half later. 

This story appeared in the news magazine La Bigarure, which, as has 
been noted, was printed at The Hague and had published the account of 
Diderot s improvising ink when he was in solitary confinement at Vincennes. 
Even previous to this, the anonymous editor of La Bigarure had shown him 
self to be well informed about Diderot, accurately attributing to him the 
authorship of his various unacknowledged works. 7 When, therefore, under 
date of 3 December 1751, La Bigarure gleefully chronicled a .fight between 
Mme Diderot and Mme de Puisieux, the account should not necessarily be 
regarded as a canard without any basis in fact. On balance, it seems to be 
testimony, however suspect and unconfirmed, that ought not to be totally 
disregarded. According to this account, which, incidentally, declared that Mme 
de Puisieux was frightfully ugly and Mme Diderot, although a second 
Xantippe, was as pretty as her rival is frightful, Mme de Puisieux one 
day insulted Mme Diderot in the street, calling out among other things, 
Here, Mistress She-monkey, look at these two children; they are your hus 
band s, who never did you the honor of doing as much for you. This 
provocation led to a very spirited brawl, which the anonymous author de 
scribes in some lines of very indifferent verse, as though he felt, as had 
Homer, Virgil, Dante, and Milton, that prose could not do justice to such 
a sublime situation. In conclusion we learn that cold water had to be poured 
upon the combatants in order to separate them, and that Diderot, mean 
while, stayed inside, afraid to show his face. 8 Whether or not the anecdote 


was a fact, at least the publicity about it was, and Diderot probably had to 
face many people who had read the story. 

If Mme de Puisieux actually made any such derisive remark about the 
lack of children in the Diderot household, she uttered a taunt the more cal- 
culatedly wounding because it was cruelly true. On 30 June 1750, little 
Frangois-Jacques-Denis, only shortly past his fourth birthday, had died of 
a violent fever and been buried the next day at the Diderot s parish church 
of Saint-Etienne-du-Mont. 9 Several months later a third child was born to 
the grieving parents and duly carried to Saint-Etienne for baptism. Laurent 
Durand, the book publisher, stood godfather for the new boy, Denis-Laurent. 
According to Mme de Vandeul, a careless woman allowed the infant to 
fall on the steps of the church on the day of his baptism. Whether this be 
true or not, certainly the baby did not live long, Mme Diderot herself 
recording that he died toward the end of the year. 10 Thus the Diderots had 
been parents three times, and were now childless. Nor was there to be an 
other baby until more than three years later. 

It was probably also in 1750 that Diderot made the acquaintance of a 
man who was to be his closest and dearest friend the rest of his life. This was 
a young German named Friedrich Melchior Grimm, son of a Lutheran 
pastor at Regensburg. Grimm, following some years of study at the Univer 
sity of Leipzig, had come to Paris as the tutor-companion of a highly placed 
young German nobleman. 11 Rousseau had made Grimm s acquaintance in 
August of I749, 12 and found him an extremely attractive person, then twenty- 
six years of age Grimm was ten years younger than Diderot greatly in 
terested in music, and already endowed with that coolly ironical but accurate 
judgment of matters artistic that he was later to display to such advantage 
in his now famous news letter, the Correspondence litteraire. 

In some ways Grimm was an adventurer, and certainly a careerist. His 
correspondence with the great furnishes rather elaborate proof that he knew 
which side his bread was buttered on. With all his elegance of manner, he 
could be ruthless, and through the years he could calmly exploit the time 
and energy of a friend like Diderot while constantly deploring that others 
desired to do so too. Because of this domineering manner with his friends, 
added to a reputed fondness for wearing face powder, Grimm s intimates 
called him The White Tyrant/ a punning reference to Tirant lo Blanch, 
the principal character of a Catalonian epic poem of the fifteenth century 
which had recently been translated into French. 13 Probably both particulars 
of the indictment were true. Certainly there is plenty of documentary evi 
dence about the face powder. Grimm s papers, sequestered during the 


French Revolution, are now in the National Archives, and there, among 
a vast collection of bills and receipts, may be found numerous ones from 
Dulac, Merchant Glover-Perfumer, at the Sign of the Golden Cradle, Rue 
Neuve-des-Petits-Champs, billing Grimm for fine powder purged with spirits 
of wine and perfumed h la marcchdk! 14 In 1750 Grimm was far from being 
the successful and much-decorated man of affairs who impressed Ambas 
sador Thomas Jefferson as being the pleasantest and most conversable mem 
ber of the diplomatic corps/ 15 He had yet to establish himself: it was to be 
some decades before Catherine the Great would be calling him in her 
letters her gobe-mouche it was a joke between them her fag. 

Rousseau, who brought Grimm and Diderot together their first meet 
ing was in Rousseau s rooms 16 was saddened to discover that each pres 
ently became fonder of the other than either was of him. Nevertheless, the 
year was not without its triumphs for Jean-Jacques, for on 9 July it was 
announced that his essay, which he had discussed with Diderot at Vincennes, 
had won the prize offered by the Academy of Dijon. 17 Diderot, with his 
usual generosity and his usual impetuousness arranged to see it through 
the press, but he gave the manuscript to the publisher instead of trying to 
make some money out of it for Rousseau. 18 In the last fortnight of November 
1750, Rousseau s startling and paradoxical contention that the development 
of the arts and sciences had been noxious to mankind was ready for public 
perusal. 19 It s catching on like wildfire, wrote Diderot to Rousseau; there 
is no example of success like it. 20 

While Diderot was seeing Rousseau s discourse through the press, he was 
also busy putting the finishing touches on the prospectus of the Encyclopedic. 
Much depended, in fame and fortune, upon presenting the proposed work 
in an attractive way. Several times in 1749 the publishers had alleged that 
they were on the point of launching the prospectus, but, probably because 
of Diderot s imprisonment, this was much delayed. According to an unpub 
lished document written in 1771 or 1772 by Joly de Fleury, the procureur 
general of France, Chancellor d Aguesseau had personally approved and 
initialed a copy of the prospectus, satisfying by this approbation the regula 
tions governing the previous submission of manuscript; and according to 
the same authority, the Lieutenant-General of Police had written on the 
prospectus, Permission for printing and posting, n November 1750. Signed 
Berryer. 21 On 21 November 1750, the publishers drew up an agreement 
upon the procedure for accepting subscriptions. 22 It seems quite certain, 
then, as is stated in the Encyclopedic itself, that the prospectus was first 
circulated in November I750. 23 Eight thousand copies of it were stitched 


(and presumably disseminated). 24 Eight thousand copies! and they are 
now rarer than the whooping crane, almost as rare as the dodo. Indeed, the 
director of the French National Archives had considerable difficulty in 
1950 in locating a copy. 25 

The salient features of the prospectus have already been described in the 
prologue to this book. In one of the closing paragraphs of his address to the 
public, Diderot spoke with humbleness of the importance and significance of 
this venture, and then, in abrupt transition, he saluted the future in what 
was a sort of dedication 


Along with the editing of the Encyclopedic and the preparation of the 
prospectus, Diderot found time in 1750 to put down his speculations in a 
new field of thought. This Lettre sur les sourds et muets & I usage de ceux 
qui entendent et qui f orient ( Letter on the Deaf and Dumb, for the Bene 
fit of Those Who Hear and Speak*) started out with some firsthand ob 
servations on the behavior of deaf-mutes and went on to canvass a number 
of interesting and original theories on linguistics and aesthetics. The work 
revealed an astonishing number of ingenious insights into the metaphysics 
of beauty and into the psychology of communication, discussing both gestures 
and word symbols. Just as a famous twentieth-century work entitled The 
Meaning of Meaning attempted to restate the problem of knowledge by 
means of a rigorous analysis of the functions of language, so Diderot in 
his century attempted to do the same thing, breaking new ground in the 
study of semantics and word symbolism. 26 

This time, Vincennes having made him cautious, Diderot submitted his 
manuscript to the proper authorities. But although the censor passed the 
manuscript on 12 January 1751, there evidently was something about it that 
caused Malesherbes, the new director of publications, to feel that he could 
not authorize its publication with Diderot s name on the title page and 
with the accolade of Avec Approbation & Privilege du Roi! 27 Instead he 
gave it a tacit permission. This curious and very common practice con 
stitutes an excellent example of the sort of paradoxical and illogical pro 
cedure that the anomalies of the ancien regime brought into being. A tacit 
permission was an official connivance at an infringement of the regulations. 28 
The practice was so general and so regularized that a register of most tacit 
permissions was kept on file by the syndics of the corporation of booksellers. 
Other tacit permissions, however, were accorded orally and without registra- 


tion, the author and printer merely being given private and non-documentary 
assurances that they might publish a particular manuscript without molesta 
tion from the police. In every case, however, the censors previously read the 
manuscripts in the usual way and the director of publications knew per 
fectly what was going on. Yet all these numerous books were printed anony 
mously, with misleading places of publication printed on their title pages, 
the point being that they should bear every mark of being illicit and clan 
destine in order to save the government from being officially embarrassed 
by any statements they might contain. The advantage to the monarchy of 
this practice was that it increased the employment of French printers and 
helped keep French money inside French boundaries. 29 

Any work that received even tacit permission was not likely to contain 
incendiary doctrine against Church or State. In comparison with the Letter 
on the Blind, therefore, the Letter on the Deaf and Dumb may have seemed 
a little dull. Although the work had three editions in 1751 and another in 
1772, and although Mme Necker, Diderot s friend and the famous wife of 
the famous statesman, thought it Diderot s best work she claimed that 
he wrote it in a single night, which seems incredible for a book of some 
seventeen thousand words 30 in general Diderot received less applause for 
it from his own generation than he does from the present one. 

Diderot did not, however, compromise in this little book any of his con 
victions regarding psychology or metaphysics. He consistently assumed that 
knowledge is completely dependent upon the senses and that therefore a 
man s answers, even his views on metaphysical questions, will be relative 
to his senses and, indeed, to the number of them. A society made up of five 
persons, each having only one of the five senses, would be, in my opinion, 
an amusing one : each would have a view of the world relative to his own 
sensory equipment, each would treat all the others as being senseless. 31 Thus 
Diderot was striking at and undermining various absolutist modes of thought. 
He did not get into trouble because this time he avoided the expression of 
inflammatory sentiment that in his previous treatise he had put into the 
mouth of the dying Saunderson. Nevertheless the Letter on the Deaf and 
Dumb incorporated and carried forward the new psychology and the new 
methodology which was so corrosive to older and more absolutist ways of 
thinking. 32 

In the course of the twentieth century the Letter on the Deaf and Dumb 
has come to be regarded more and more highly, not only as a document 
for establishing Diderot s extraordinary versatility and sensitivity but also 
as a book intrinsically valuable because of the light it throws on fundamental 


problems of poetics. Professors Torrey and Fellows call it one of the out 
standing examples of literary criticism in the eighteenth century/ and con 
tinue: In this first essentially scientific study of the deaf and dumb, Diderot 
was interested in the art of communication by gesture and of the relationship 
between gesture and language. From the great actor who projects in gestures 
what he expresses in words, we are led to the deaf mute who, standing 
before a color-organ, at last surmises what music is like language, a means 
of communication. This was deduced from the fact that, often before as in 
conversation, he had watched people s faces and expressions while music 
was being played outside his world of silence. There follows a discussion 
of the theory that the painter is capable of portraying but a single moment 
within which the past and future should be suggested, whereas the poet is 
able to depict a succession of moments. The conclusion is drawn from this 
that some subjects are best described in one medium, some in the other. 
(The debt of Lessing s Laofyoon to Diderot need hardly be insisted upon.) [ 33 ] 
But, we are told, the poet should realize that he is dealing with words, and 
words have both meaning and sound. The superior poet will then paint 
in sounds what he is expressing in meaning. Furthermore, poetry is the 
interweaving of hieroglyphs, that is, a series of pictures representing ideas. 
In this sense, Diderot adds, all poetry is "emblematique" or symbolical, but 
only the poet of genius succeeds in saying the inexpressible. Thus the reader, 
who has almost forgotten that he started out by reading a brief essay on 
the deaf and dumb, finds he has arrived at an esthetic theory which leads 
directly to Baudelaire and the Symbolists by means of certain fundamental 
principles which, quite possibly, have not yet been fully explored. 34 

Diderot s doctrine that the words the poet uses are fraught with elusive 
and magical overtones has caught the imagination of contemporary critics, 
especially since he referred to such words as hieroglyphs, thus calling par 
ticular attention to their symbolic nature. 35 This theory seems a little startling 
in contrast to the formal verse much of it exceedingly earth-bound 
that the age composed; and it is the enunciation of a doctrine such as this 
that makes Diderot seem so modern to the aestheticians and the creative 
experimenters of the nineteenth and twentieth centuries. 86 It was partly 
because Diderot was so proficient a classicist that this theory occurred to 
him. For the examples he cites are taken not simply from Corneille, Racine, 
Voltaire, and Boileau, but from the Greek of Epictetus and the Latin of 
Cicero and the Italian of Tasso. Rhythms and the quantities and stresses of 
syllables, with their subtle and elusive intertwining of sense impression and 
meaning, fascinated him. Can we not, as a French critic has recently sug- 


gested, can we not hear Diderot in these passages, declaiming with that 
accompaniment of gesture that was habitual with him and of which he was 
so fond? 37 He analyzes, much as Ruskin analyzed a passage of Milton in 
Sesame and Lilies, some of the haunting passages from the Iliad and the 
Aeneid> from Ovid and from Lucretius. All this inevitably disappears in 
translation,* he wrote, even in the best. 38 

Modern critics, speaking of the Letter on the Deaf and Dumb, are likely 
to concur with a scholar who recently spoke of Diderot s mind as being 
like one of those complicated modern rockets which startle by the unsus- 
pectedness and apparent inexhaustibility, as well as by the brilliance of their 
evolutions. 39 The same point was made by the Abbe Raynal at the time, 
but in a much less complimentary vein: M. Diderot speaks on this occasion 
of a thousand things, on metaphysics, poetry, eloquence, music, etc., which 
have only a very tenuous connection with the principal subject. This letter 
is not pleasing, but it is instructive. . . . Everything that comes from M. 
Diderot s pen is full of new viewpoints and of well-grounded metaphysics; 
but his works are never finished: they are sketches; I doubt whether his 
vivacity and his precipitation will ever permit him to finish anything.* 40 
This is one of the earliest examples of what came to be in the eighteenth 
and nineteenth centuries a commonplace of criticism of the works of Diderot. 
The Letter on the Deaf and Dumb was by way of being a criticism, and 
by no means a gentle one, of a work published not long before that had 
sought to discover a single unifying principle of beauty applicable to all 
the fine arts. This book was the Abbe Charles Batteux s Les Beaux-Arts 
reduits a un mtme princife (1746), and Diderot, in his allusions to it, could 
be conceived to have gone considerably beyond the call of duty. 41 All these 
personalia are forgotten now, and only Diderot s interesting insights into the 
problems of aesthetics remain, but it need not be overlooked that Diderot 
had a taste for polemics and that his personality generated heat, causing 
both him and the people with whom he was in contact to glow, whether 
with a gratified sense of fellow feeling or with a consciousness of exasperated 

A few weeks later Diderot published what amounted to the second edition 
of the Letter on the Deaf and Dumb, with additions. His introductory re 
marks were dated 3 March 1751, and D Hemery noted in his journal for 
20 May that the Additions to Serve as Clarification for some of the Passages 
in the Letter on the Deaf and Dumb was already published, with Males- 
herbes tacit permission. 42 Diderot says that these additions were written in 
reply to the comments and criticisms of a very intelligent young woman of 


his acquaintance, Mile de La Chaux, whose pathetic love story he tells in 
one of his highly regarded short stories, Ceci n est pas un come (This Is No 
Yarn ) , 43 In the same edition was also printed Diderot s lengthy observations 
in rebuttal of criticisms his book had received in the April issue of the 
Journal de Trevoux** 

Meanwhile, the publication of the prospectus had brought about a short 
but sharp passage at arms between Diderot and the Jesuit editors of that 
same periodical, the first skirmish in what was to become a bitter and pro 
tracted war. Diderot was a formidable antagonist, but so were his opponents. 
They were led by the chief editor, Father Berthier, an able person who car 
ried on the Journal de Trevoux, it was said, to the satisfaction of all, as 
much for his skill in digesting works as for his prudent moderation in 
criticisms and eulogies. . . . 46 He was certainly moderate in his eulogy of 
the prospectus : in his first number for 1751 he quite patently implied that 
the celebrated chart or scheme of human knowledge that the prospectus 
contained was nothing but a barefaced plagiarism of Bacon: The editors, 
MM. Diderot and d Alembert, make known with reference to this system 
that they have principally followed Chancellor Bacon, author of the book 
On the Dignity and Increase of the Sciences. And this is so true that we 
intend to fall in with their views, while giving pleasure to the public, by 
printing an extract that will compare the work of the Chancellor with the 
Prospectus of the Encyclopedic, especially in regard to the tree of human 
knowledge/ In this extract, which appeared in the next issue, the editors 
found that the system of this learned Englishman was followed point by 
point and word for word by our Authors. 46 

At this juncture Diderot took fire, and not without cause. He had expressly 
stated in the prospectus his obligations to Lord Bacon, so that the imputa 
tions of the Journal de TrSvoux seemed all the more unfair, unnecessary, 
and aggressive. Perhaps the antagonism of the Journal de Trtvoux in this 
connection can be explained, as was propounded at the time, by the Jesuits 
previous expectations of being asked to take an important share in con 
tributing to the EncyclopSdie D Alembert later stated that their fury was 
caused by the refusal to confide to them the theological part of the Encyclo 
pedic 47 and their subsequent vexation at finding themselves ignored. 

Diderot s response to this attack was in the form of a pamphlet containing, 
by way of sample, his forthcoming Encyclopedic article on Art, and also, 
more to the point, an open Letter from M. Diderot to the Reverend Father 
Berthier, Jesuit.** This was a vigorous exercise in polemics, but contained 
nothing of interest beyond the dispute itself, although the contemporary 


journalist Clement spoke of it as being full of fire, wit, and charm/ 49 The 
Journal de Trevoux in turn replied, Diderot is a man o intelligence, and 
there is pleasure in receiving his letters when they concern literature. Other 
matters are too dangerous, he knows very well/ This exordium, sounding 
very ominous and menacing, was followed by a sneer: Several of these 
gentlemen of the Encyclopedic are known to us; we hold them in high 
esteem; they have competence, politeness, morals, and religion. M. Diderot 
has given a singular proof of his modesty by not naming them after him 
in the frontispiece of the Prospectus. Their names would have shed a great 
luster upon his. 50 

The Second Letter of M. Diderot to the Reverend Father Berthier was 
written at nine o clock in the evening of 2 February 1751, when Diderot 
was still red-hot from having just read the offensive article in the Journal de 
Trevoux. 51 D Hemery, when noting in his journal that Malesherbes had 
granted permission to publish this reply, described it as a very judicious 
work. 52 This may be so; but its arguments were simply ad hominem, 
and there is nothing in the letter that has survived in interest the storm and 
stress of the occasion that produced it. 

It is a matter of doubt whether Diderot was wise to engage in such a 
dispute. Evidently the publishers of the Encyclopedic had misgivings on this 
point, for Diderot mentions in an undated letter that clearly seems to refer 
to this time and probably to this incident that Messieurs the associates . . . 
were not in favor of printing it. 53 But whether wise or not, the exchange of 
salvos served to engage the public interest, as was evidenced by the publica 
tion of a number of pamphlets, all of them now very rare, regarding the 
dispute. One of these, a four-page Lettre a M. * * *, de la Societe Royale 
de Londres, was thought by D Hemery to emanate from Diderot s circle 
or even to have been written by Diderot himself. 54 While appearing to blame 
Diderot, it awarded him all the honors of the combat: M. Diderot, who is 
known to be a man of genius, gifted with a very brilliant imagination, and 
who enjoys a merited reputation, has had the weakness to write to Father 
Berthier with a vivacity which even his greatest partisans have disapproved 
of. His letter is in truth full of ingenious sallies, its style is firm and con 
cise, but one might almost say that each sentence is a poignard wrapped up 
in a bolt of lightning. Poor Father Berthier! 

A Jesuit whom Diderot greatly admired evidently wrote to him at this 
juncture, endeavoring to moderate the dispute. This was Father Castel, a 
benign and ingenious person who is remembered as the inventor of a color- 
organ, a harpsichord-like instrument the intent of which was to suggest 


sensations of melody and harmony by combining multi-colored ribbons 
rather than sounds. Diderot frequently mentions this machine for example, 
in Les Bijoux indiscrets, in the Letter on the Deaf and Dumb, and in the 
Encyclopedic as creating what he calls ocular music or sonatas in color. 55 
Father Castel s color-organ was of scientific interest because, as Diderot 
himself realized, it raised a number of interesting and complicated psycho 
logical problems, in particular the phenomenon of inter-sensory association 
now called by the name of synesthesia. 56 Father CastePs organ was, indeed, 
one of the most philosophical inventions of the eighteenth century. 

Diderot received Father Castel s letter with great respect, although it did 
not modify his sense of grievance. But in the name of God, reverend Father, 
he replied, what is Father Berthier thinking about to persecute an honest 
man who has no enemies in society other than those he has made for himself 
by his attachment to the Society of Jesus and who, displeased as he ought to 
be, has nevertheless just refused with utter contempt the weapons he has 
been offered against it? This virtuous feeling arose from the fact that just 
after the publication of his second letter to Berthier, Diderot had received a 
note proffering information and money if he would use them against the 
Jesuits. 57 It is clear that Diderot s letters to Berthier caused something of a 
sensation, for although the Jesuits were used to being opposed by Jansenists, 
this was one of the very first occasions when their position was openly chal 
lenged by a philosophe.^ 

Spring of this year brought a scholarly and academic honor to Diderot, and 
one of which he could make very profitable display. The Prussian Royal 
Academy of Sciences and Belles-Lettres made him a member, just in time to 
allow him to mention it on the tide page of Volume I of the Encyclopedic. 
Diderot s letter of thanks to Formey, the secretary, was dated 5 March 1751. 59 
It was Diderot s first academy and, even in a century pullulating with 
academies of various kinds, almost his last. It is preposterous, but still true, 
that the man with one of the most seminal minds of the century should have 
gained admittance to no more academies than the Prussian, two Russian ones, 
and the Society of the Antiquaries of Scotland. It was not because he spurned 
invitations, for the evidence is pretty clear that he joined every academy 
or learned society that ever asked him. The fact was that Diderot s thought 
was too radical and came too close to being openly atheistic to qualify him 
for membership in the most respectable and sedate circles. It might be 
supposed that the Royal Society of London, not being so committed to an 
official orthodoxy as were the French academies, might have extended him 
a bid, especially since they invited not only D Alembert but also the inde- 


fatigable and rather limited Encyclopedist, the Chevalier de Jaucourt. But 
apparently, as D Hemery noted in his journal in 1753, the Royal Society 
resented Diderot s insinuation in his Letter on the Blind that one of their 
former members, the blind Saunderson, had died an atheist resented it to 
the point of blackballing him permanently. 60 

Even the membership in the Prussian Academy was evidently something 
of a quid pro quo. Beginning in 1742, Formey had been collecting materials 
for an encyclopedic compilation, and these he offered to the editors of the 
Encyclopedic after the prospectus of 1745 had appeared. 61 The account book 
of the publishers shows that in 1747 they contributed three hundred livres 
toward the acquisition of these manuscripts and promised to send Formey 
a set of the Encyclopedic free of charge and to name him in the preface. 62 
Diderot acknowledged these manuscripts very handsomely in his prospectus 
but without mentioning that they had been paid for, and one can only put 
two and two together when three months later he was made one of Formey s 
academy colleagues. 

Public anticipation of the appearance of Volume I was increasing, whetted 
not only by the controversy with the Journal de Trevoux, but also by the 
sample article on Art which Diderot published. 63 c lt will be the best dic 
tionary of things that there has been up to now, wrote the anonymous author 
of the Lettrc & M. * * *, de la Societe royale de Londres. The prodigious 
multiplicity of its contents, its extensiveness, and the advantage of a large 
number of plates showing the work of various artisans, cannot but make 
it useful, interesting, and curious. 64 No less a person than Buffon, writing 
in December 1750, had said that the authors had shown him several articles 
and that the work was going to be good; and again in April, he remarked 
of Volume I, 1 have gone through it; it is a very good work. 65 The official 
censor, writing on 24 June, gave it a very resounding compliment indeed: 
By order of My Lord the Chancellor I have read in the first volume of the 
Encyclopedical Dictionary the articles concerning medicine, physics, surgery, 
chemistry,, pharmacology, anatomy, natural history, and in general every 
thing that does not appertain to theology, jurisprudence, or history. 

The various subjects have appeared to me to be well treated therein, 
conformable to the arrangement, extensiveness, and clarity that they de 
mand: and I am of the opinion that the editors of this great work are be 
ginning to carry out in a very satisfactory manner the vast plan that they 
sketched in the prospectus which the public received so warmly. I found 
nothing in this first volume that does not merit being printed/ 06 

As the reputation of the Encyclopedic grew, so did the list of subscribers, 


which stood at 1,002 in April of 1751 and 1,431 in July. 67 Meanwhile, on 
28 June 1751, the much-heralded volume was published. 68 Its title page, simple 
as eighteenth-century titles go, ran as follows: 




By a Society of Men of Letters. 

Placed in order and published by M. Diderot, of the Prussian Royal 
Academy of Sciences and Belles-Lettres; and, for the mathematical 
portion, by M. d Alembert, of the Royal Academy of Sciences at Paris, 
of that of Prussia, and of the Royal Society of London. 


Published by Briasson, the elder David, Le Breton, and Durand 

With Approbation and License of the King. 


What Readers Found in Volume I 
of the. Encyclopedic 

THE public that greeted the first volume of the 
Encyclopedic was neither impartial nor indifferent. 

Readers were in a mood to be particularly responsive to or particularly 
repelled by what they found therein. And what they found was a book 
that purported to be a book of reference but was in fact a sort of political tract. 
It was a work which, in the course of imparting information, helped to 
transform men s values. It was a work which helped to make men favorable 
to change. Historians are agreed that the Encyclopedic played an extremely 
important part as one of the disposing causes of the French Revolution. It 
was, in short, a publication with a profound political impact. 

The Encyclopedic was like a great modern newspaper with a strongly 
defined editorial policy, one which is not always acknowledged but which, 
far from being confined to its editorial page, creeps into its reporting and even 
into its special features and comic strips. There was a great deal of skillful 
editorializing in the columns of the Encyclopedic. To use a term with un 
pleasant connotations, we must fairly admit that the authors of the Ency 
clopedic were propagandists. Yet in their behalf it can also be said that they 
were propagandists not in the too frequent sense of sophists industriously 
and knowingly attempting to make the worse seem the better cause, but in 
the more gracious sense of propagandists who recognize no higher authority 
than truth, who are convinced that they are in search of it, and who prop 
agandize for what they are certain will enlighten and profit mankind. And 
because the Encyclopedic was pre-eminent in its field, its effectiveness as an 
instrument of propaganda was all the greater. Its audience was almost a 
captive one: the wariest and most sophisticated of its readers, as well as the 
most gullible and ingenuous, found it indispensable. 



Not only was the Encyclopedic a work that hoped to persuade its readers 
to a certain point of view, but also a publication that, because of the conditions 
of censorship, had to pick its way with extraordinary care whenever it alluded 
to matters involving politics or theology. Any criticism of existing conditions 
had to be exceedingly oblique and indirect, for this was a publishing venture 
completely dependent upon official authorization. How else arrange for a 
subscription list, without which the enormous work would be financially too 
precarious? How else carry through successfully all the editorial complexities 
of so large an undertaking? Accordingly the sophisticated soon realized that 
it was necessary not only to read the lines of the Encyclopedic but also be 
tween them. The public soon learned to identify, whether with alarm or 
delight, the manifold contrivances of editorial guile. The Encyclopedic fasci 
nated, quite as much because of what did not meet the eye as because of the 
new features and devices that did. 

After the flowery dedication to D Argenson which so bruised the spirit of 
Diderot, Volume I was introduced by a lengthy Preliminary Discourse 1 
which set the tone for the ensuing work. This essay has been much admired 
by contemporaries and posterity alike, one modern editor placing it on a 
level with Descartes Discourse on Method in scientific merit, and surpassing 
it in literary. 1 This much-praised piece was written by D Alembert, not 
Diderot. Why is not known, unless perhaps it was on the theory that so 
conspicuous a part should be written by an editor who had not spent time 
in prison. 

The Treliminary Discourse 1 was moving and persuasive because it con 
veyed and communicated the editors spacious faith. It is patently a docu 
ment written by a man who wishes well for mankind. And the conviction 
it imparts is not so much to use one of Diderot s phrases an eloquence 
that one hears as a persuasion one breathes in. From its lines shines the 
faith that knowledge will make men better, will make them more the 
masters of themselves as well as of their environment, will give them light. 
And there is pride in these pages, too the pride that comes from feeling 
that the Encyclopedic will help to make this knowledge secure. May the 
Encyclopedic become a sanctuary where men s knowledge may be pro 
tected from revolutions and from time. 2 

The Treliminary Discourse is at once an exercise in epistemology and an 
intellectual history, albeit a somewhat episodic one, of Europe since the 
beginning of the Renaissance, done in the light of philosophy with the 
technical rigor of a mind profoundly mathematical. 3 In the epistemological 
part, D Alembert inquires whence human beings derive their ideas and 


answers this fundamental question as Locke had: All our direct knowledge 
is reduced to that which we receive by way of our senses; from which it 
follows that it is to our sensations that we owe all our ideas. 4 The original 
statement of the dictum that nothing exists in the mind that has not been 
first in the senses (Nihil est in intellect* quod non fuerit in sensu) appears 
in Aristotle and had been quite readily accepted by the medieval scholastic 
philosophers. In the eighteenth century, however, the expression of this 
psychological concept, while not precisely heterodox, almost invariably made 
the devout exceedingly nervous, for it came close to denying the sovereign 
quiddity of the soul. The Lockean view proclaimed that human beings are 
not born with innate ideas of religion and morality, but simply derive 
them from their experience. Moreover, the Lockean psychology could be 
interpreted as coming very close to materialism, very close to the idea that 
sense impressions exist, that neurological impulses exist, but that the soul 
as an independent entity does not. Anybody who, like Diderot in his Letter 
on the Blind and now D Alembert in the Preliminary Discourse, 5 emphasized 
the role of the senses in cognition could expect to earn the praise of people 
seeking positive knowledge without conventional metaphysical integuments, 
but at the same time to win the distrust or censure of persons who felt that 
this view had in it something inherently irreverent and dangerous. 

After his analysis of the bases of psychological knowledge, D Alembert 
lengthily discussed the various branches of learning, linking them together 
and grouping them under the three general components of the understand 
ing, namely, memory, reason, and imagination. This was a scheme which 
he, like Jefferson in classifying his library, borrowed from Bacon. This part 
of the discourse corresponds to a visual scheme of human knowledge that 
was folded into Volume I following the Preliminary Discourse. 5 In this 
elaborate Systime figure des connoissances humaines, a diagrammatic 
depiction that aroused much admiration at the time, the editors arranged the 
various subjects in parallel columns. They gave the generic name of History 
to all the branches of knowledge in the column allocated to the memory; of 
Philosophy to all that they deemed to be principally dependent upon the 
reason; and of Toetry to those dependent upon the imagination. Such a 
visual presentation of the relationships existing among the various branches 
of knowledge was plausible, and yet it betrays many of the prejudices and 
predilections of its contrivers. It is enlightening to notice how the editors 
have placed in visual and organic relationship two of the master words, the 
dynamic symbols of the age, Philosophy and Reason, each enhancing the 
prestige of the other. In contrast, History is relegated to a very secondary 


position. It emanates from mere memory. This refusal to allow history to 
partake of the honors of philosophy or to consider itself as stemming from 
reason is one of the intellectual idiosyncrasies of the Encyclopedist school. 

It was typical of the whole point of view of the Encyclopedic, and quite 
representative of the intentions of Diderot, that theology and religion were 
slyly relegated to a small, almost infinitesimal, area in comparison with the 
eye-filling space taken up by the subjects of positive knowledge. Divine 
Science bulked just about as large spatially as The Manufacture and Uses 
of Iron. Such were the Encyclopedias unacknowledged ways of waging 
psychological warfare: for this was not the fashion in which the relative 
significance of things was understood by the faculty of theology of the 
University of Paris. 

In the second half of his Preliminary Discourse, D Alembert briefly 
but masterfully indicated the contributions to knowledge made by many of 
the great names : principally Bacon, Descartes, Newton, Locke, and Leibniz. 
This was brilliantly done, and D Alembert was highly complimented on his 
effort by such great persons as Buffon and Montesquieu, while Raynal wrote 
to his subscribers that 1 believe it to be one of the most philosophical, logical, 
luminous, exact, compact, and best written pieces that we have in our 
language. 5 

Not that the Preliminary Discourse was without its blind spot. It is 
worthy of remark that D Alembert dates the history that he thinks really 
matters as beginning practically with the Renaissance. The reason for this 
was plain: both he and Diderot regarded medieval times as hopelessly 
obscurantist and priest-ridden, and the best thing that could be said of 
their own century, they thought, was that it resembled the Middle Ages 
so little. It was exceptionally difficult for men of the French Enlightenment 
to feel that medieval history had had any real significance save of a negative 
and deplorable sort. To them the history of the Middle Ages seemed an 
interruption instead of a continuum, and because of this belief, they never 
developed a philosophy of historical continuity or an attitude of historical- 
mindedness, relying upon knowledge of the past to illuminate the future, 
as did the nineteenth century. 6 Contrast for a moment their habit of mind 
with that of Edmund Burke, whose feeling for history was so profound 
that he declared that society is indeed a contract, binding the present genera 
tion to the ones that are dead. The Encyclopedists were apt to feel, as J. B. 
Bury remarked, a sort of resentment against history. 7 And because eighteenth- 
century men wanted their own age to be an Age of Reason, they had little 
praise for an Age of Faith. This astigmatism was common to a large part 

I 34 

of the Enlightenment, which felt none of the filial devotion of a Henry 
Adams yearning for Mont Saint-Michel and Chartres 

As to the Preliminary Discourse as a whole, it i. fair to say that though 
D Alembert wrote it, Diderot heartily agreed with it. And if we should 
ask how the Preliminary Discourse would have Offered _had Diderot 
written it, the correct answer would be very little, save that Diderot : wodd 
probably have based his argumentation more on biological modes of thought, 
whereas D Alembert used the mathematical. 

The Encyclopedic was novel in that it was a co-operative work written 
by several hands, and more unusual still in that it identified its contributors. 
According to the Preliminary Discourse, articles marked with an asterisk 
were written or revised by Diderot in his capacity as editor; but unsigned 
articles without any identifying mark were also written by him; other 
articles were initialed according to a scheme of symbols published in the 
prefatory pages. The final pages of the Preliminary Discourse were taken 
up with identifying and thanking the contributors. 

As a reader turned to the body of the work, his first impression might have 
been of surprise that the Encyclopedic was organized alphabetically. It 
might have been supposed that, having dilated so much upon his chart of 
human knowledge, Diderot would have organized his presentation according 
to this system rather than according to the alphabet. Evidently the editors 
were uneasily self-conscious about this point, for they discuss at length why 
they did what they did, the reasons appearing to be in part solid and in 
trinsic, in part (like Mr. Guppy s) owing to circumstances beyond their 
control 8 The Encyclopedic was criticized now and again for its arrangement, 
yet subsequent experience seems to have proved that the alphabetical presen 
tation in reference books, although less logical, is also less confusing. 

The Encyclopedic endeavored to compensate for this lack of the systematic 
by freely using cross references to indicate close and organic connections. 
Chambers had done this and it has become, of course, a commonplace in 
the construction of reference works; but for the Encyclopedic the apparatus 
of cross references served a further purpose. It slyly suggested points of 
view that, because of censorship, could not be openly canvassed. 

Twentieth-century commentators naturally dwell on the most important 
usually the lengthiest, articles that the Encyclopedic contains. To the casual 
contemporary reader, however, the work might have seemed most impres 
sive because of the multiplicity of its brief entries; there were hterally thou 
sands This is explained by the fact that the Encyclopedic, although it con 
tained no maps, attempted to be a gazetteer. Moreover, it also served as a 


dictionary, defining numerous words, some of them very common ones, 
and often giving elaborate examples of synonyms. The study of synonyms 
had become popular in France since the publication o a book of them by 
an Abbe Girard in 1718. The Ency dope die frequently copied Girard, usually 
with acknowledgments, and often printed synonyms and illustrations of its 
own. Diderot was proficient in this department, as when, to give a very 
Gallic example, he distinguished between the figurative meanings of to 
bind and to attach* by adding to the Girard examples : One is bound to one s 
wife, and attached to one s mistress/ X1 

The Encydopedie also contained, besides these definitions and synonyms, 
a large number of highly regarded articles about grammar, some of them 
very lengthy, and most of them done by an amiable old freethinker named 
Dumarsais. We believe ourselves able to say/ Diderot had written in the 
prospectus, that no known work will be as rich or as instructive as ours 
concerning the rules and usage of the French language, or, indeed, on the 
nature, origin, and philosophy of languages in general/ Moreover, the editors 
of the Encydopedie were extremely aware of what is now called the problem 
of semantics: How many questions and vexations would one spare oneself 
if one were finally to determine the meaning of words in a clear and precise 
manner/ wrote D Alembert in his Preliminary Discourse/ thus capping 
his earlier remark that we owe many errors, as some philosophers have 
noticed, to the abuse of words. . . / 12 

A modern reader interested in biographical information finds the Ency 
dopedie lacks an alphabetical listing of personages. Volumes following the 
second occasionally include some biographical information, but, oddly 
enough, listed under the name of the city in which the person was born. 
As much as the Encydopedie was admired, it was distinctly deficient in 
articles of biography and systematic history. Their inclusion would have 
greatly increased its size, and the editors therefore referred their readers, 
not very satisfactorily, to a current historical and biographical dictionary, 
Moreri s Grand dictionnaire historique, first published in 1674 and followed 
by a number of editions and supplements. 13 

In other respects the Encyclopedic had very adequate coverage, with ample 
articles on the inescapable subjects of theology, philosophy, and belles-lettres. 
It made its special reputation, however, on both scientific articles and those 
describing the technology of the arts and crafts. In the first volume were 
found lengthy articles by Diderot on Steel (Acier), Agriculture/ 14 Silver* 
(Argent), Needle (Aiguille), and Accouchement/ as well as important 
articles by him on more conventional subjects, such as analyses of the 


philosophy of the Arabs, the Hindus, and of Aristotelianism. Other con 
tributors wrote important articles on such topics as Bee (Abeille), Anatomy 
(twenty-eight pages where Chambers had had only one column), Trees 
(Arbre), Attraction, Alsace (mainly about the mines in that region), At 
mosphere/ Slate (Ardoise), Magnet (Aimant), Alkali/ etc. These sub 
jects were described with an attention to technical and technological detail 
that was always one of the most conspicuous features of the Encyclopedic, 
a feature that made it representative of a new social class and of a new 
outlook on man. This attention to up-to-date technology is admirably dis 
played, for example, in Diderot s own article on Boring Machine (Attsoir). 
What he was describing, with information as to how it could be constructed, 
was a machine for making cannon from solid castings. An anecdote, in 
cidentally revealing the wide distribution of the Encyclopedic, will show 
how useful this sort of information could be. About 1773 ^ e Ottoman 
Sultan commissioned a soldier of fortune, the Baron de Tott, to build up 
the Turkish artillery and arm the forts on the Dardanelles. Tott had to 
manufacture the cannon he needed, without having had previous experi 
ence in the work. A Greek, very expert in the Art of constructing Mills/ 
Tott wrote in his Memoirs, was, however, of much service to me in making 
my boring Machine. The Memoirs of Saint Remi and the Encyclopedic 
were my constant guides and I wanted no other till I came to make the 

Moulds ____ 15 

In short, the Encyclopedic was practical It was useful. And since it con 
tained much information unobtainable elsewhere, it was indispensable. The 
Chevalier de Jaucourt pointed out these characteristics when he wrote of the 
Art of Heraldry in an Encyclopedic volume published in 1765: There does 
not exist a single pamphlet on the art of making shirts, stockings, shoes, 
bread; the Encyclopedic is the first and unique work describing these arts 
useful to men, while the book trade is inundated with books on the vain and 
ridiculous science of armorial bearings. ie 

Diderot s interest in technology, in the crafts, and in the mechanical arts 
is very typical of him. There was nothing factitious about this interest in 
the practical On the contrary, it sprang directly from his social origins, from 
the microcosm of the tanners and the cutlers of Langres, from the pride in 
workmanship and the canniness in money matters of the self-respecting 
craftsman who begot him. Diderot always respected craftsmanship, and 
although he sometimes spoke disdainfully or despairingly of the people 
and employed the word in much the sense that we now give to the masses/ 
he never spoke disparagingly of the artisan or his social usefulness. It was 


this attitude, faithfully reflected in a thousand places in the Encyclopedic, 
that made the work so revolutionary. New values were here being set forth 
and admired, the dignity of just plain work was being extolled. Upon 
examining the products of the arts/ wrote Diderot in his Art article, 
one has observed that some were more the work of the mind than of the 
hand, and that others, on the contrary, were more the work of the hand 
than of the mind. Such is in part the origin of the pre-eminence accorded to 
some arts over others, and of the classification of the arts into liberal arts 
and mechanical arts. This distinction, though well grounded, has had the 
unfortunate effect of degrading people who are very estimable and very 
useful, and of strengthening in us a certain sort of natural laziness which 
already was inclining us only too much to believe that to devote a constant 
and continuous attention to experiments and to individual, palpable, and 
material objects was to detract from the dignity of the human mind, and 
that to practice or even to study the mechnical arts was to lower oneself 
to things that are laborious to study, ignoble to meditate upon, difficult to 
expound, dishonoring to trade in, inexhaustible in number, and in value 
trifling. A prejudice tending to fill the cities with prideful praters and useless 
contemplators, and the countryside with petty tyrants, ignorant, idle, and 
disdainful. Twas not thus that Bacon thought, one of England s foremost 
geniuses; nor Colbert, one of France s greatest ministers; nor, indeed, the 
just minds and the wise men of any era. . . . How bizarre are our judg 
ments! We demand that people should be usefully engaged, and we disdain 
useful men/ 17 These views are of great interest in themselves. Moreover, 
Diderot attached extraordinary importance to them, a fact proved by his 
publication of this article in advance, as a sample of the whole encyclopedia. 
It is evident that he intended to fix public attention upon this aspect of the 
new work. 

In congruence with its interest in the crafts and technology, the Ency 
clopedic manifested an equal interest in the problem of dignifying or creating 
an adequate and accurate vocabulary for them; . . . a science or an art 
commences to be a science or an art only when acquired knowledge gives 
rise to making a language for it/ wrote the author of the article Anatomy/ 18 
Diderot himself had referred in his prospectus to the importance of nomen 
clature and returned to the subject, discussing it at some length in his article 
on Art/ In the opinion of the principal historian of the French language, 
the Encyclopedias interest in accurate and sufficient nomenclature is one of 
its most valuable characteristics. The Encyclopedic nonetheless remains the 
first and chief homage of the eighteenth century to the language of artisans 


... a powerful effort not only to disseminate the knowledge of the arts 
and sciences but also to rehabilitate technical terms. 19 

It would not have taken long for a reader of the first volume to discover 
that the Encyclopedic was interested in more than simply warming over old 
themes, reviving or inventing technical terms, or presenting subjects never 
before allotted space in a work of this kind. More than these, the Ency 
clopedic was interested in the scientific method. Indeed, it became an arsenal 
in which the weapons of critical thought were kept polished, whetted, 
and instantly at hand. Perhaps the greatest function of the work in the 
estimation of its editors was that of making people more aware of the 
methodological problems that constantly beset the acquisition of knowledge 
and the pursuit of truth. 

Obviously this was a campaign that had to be conducted on many fronts. 

One of them was the attack on words or names that in reality were devoid 

of meaning. Diderot s technique was to call attention to names, especially 

of plants and animals, about which little more was known than simply the 

empty name itself. For example, he wrote about Aguaxima: *A plant of Brazil 

and of the islands of southern America. That is all that we are told of it; and I 

would willingly inquire for whom such descriptions are made. It cannot 

be for the natives, who very likely know more characteristics of the aguaxima 

than this description includes, and who have no need of being told that 

the aguaxima grows in their country; it is as if one said to a Frenchman 

that the pear tree is a tree that grows in France, in Germany, etc. Nor can 

it be for us; for what does it matter to us whether there be in Brazil a tree 

named aguaxima, if we know only its name? What purpose does the name 

serve? It leaves the ignorant in the condition they were; it teaches others 

nothing. If it happens, then, that I mention this plant, and several others 

equally poorly described, it is out of condescension for certain readers who 

prefer to find nothing in a dictionary article, or even to find nothing but 

silliness in it, than not to find the article at all* 20 Similarly, of the word 

Aguapa f : A tree that grows in the West Indies, the shadow of which is 

said to cause the death of those who sleep in it naked, while it causes all 

others to swell up in a prodigious fashion. If the natives of these countries 

do not know it better than it is identified for us by this description, they 

are in great danger. 5 21 And in discussing the word Acalipse* he remarked, 

Here is another one of these beings ... of which one has only the name; 

as if one did not already have too many names empty of sense in the sciences, 

arts, etc. 22 

Comments such as these would seem absurdly out of place in a present- 


day work of reference. But the seekers after positive knowledge who edited 
the Encyclopedic had a useful purpose in mind. Not only did they intend 
to make their readers more critical and sophisticated in the nomenclature 
of plants and animals, they also aimed, although somewhat furtively and 
indirectly, at various high-sounding metaphysical and religious abstractions. 
No doubt the et cetera that concluded the preceding quotation referred to 
these, thus putting a cutting edge on what is usually a dulled and lazy ab 
breviation. True philosophy, wrote the author of the article To Act (Agir), 
would find itself considerably briefer if all philosophers would be willing, 
like me, to abstain from speaking of what is manifestly incomprehensible. 23 

Another methodological front upon which the Encyclopedic conducted a 
campaign was that of the credibility of various kinds of evidence. Obviously 
this tactic was primarily to unsettle convictions concerning miracles and 
the truthfulness of Genesis, but it had a broader purpose, one applicable 
to all aspects of thought and not simply the religious and the theological 
The skepticism of the Encyclopedic exercised itself overtly and entertainingly 
on old wives tales and vulgar errors, with the charm of seeming to take the 
reader into partnership. But the very same methods that were used to 
expose ignorance and superstition and sham in regard to pagan gods, ancient 
oracles, and nonexistent animals and plants Agnus Scythicus, for example 
were also the ones that, by implication, led straight to the attack upon 
more portentous obscurantisms. 

Of course the Encyclopedic had had predecessors in preaching the virtues 
of skepticism. The most important among them was Pierre Bayle (1647- 
1706), one of the great names in the history of free intellectual inquiry. 
Bayle was a French Huguenot refugee of awesome erudition, especially in 
the fields of theology, mythology, ancient history, and ancient geography, 
as well as the history of Europe in the sixteenth and seventeenth centuries. 
In 1697 he published his Dictionnaire historique et critique, a work which 
demonstrated the use to which crafty cross references could be put and a 
work, too, which bristled with such scholarship that it contains footnotes on 
footnotes. Bayle was a believer, though a critical one; and his skepticism, 
combined with his erudition, gave him the sort of dazzling intellectual 
authority over young people impatient of cant that H. L. Mencken enjoyed 
in the 1920 $ in America. But it was not an influence that could be safely 
acknowledged, especially if one happened to live in France. Bayle, then, 
should be remembered as perhaps the greatest exemplar and inspiration of 
the critical methodology preached by the Encyclopedic. If his influence was 
more negative than positive, if he showed none of Diderot s interest in 


the crafts and technology and other practical matters, still his work is 
incontestably the real ancestor of the Encyclopedic, from the point of view 
of ideas as well as form, and it has been well said that he cleared the ground 
for the steam-roller of the Encyclopedists. 24 It is almost literally true that his 
was the great unmentioned and unmentionable name of the Encyclopedic?* 

Bayle s skepticism was far from nihilistic. Quite to the contrary, it was 
of a fruitful sort, dedicated to the search for truth. Bayle, like his successors 
in the eighteenth century, thought of skepticism as a kind of detergent, the 
use of which would reveal truth. This was precisely Diderot s point of view. 
As early as the Pensees philosophiques he had declared that skepticism is 
therefore the first step toward truth, and his daughter says that the last 
words she heard him say it was the evening before he died were: The 
first step toward philosophy is unbelief. 26 This was the spirit in which the 
Encyclopedic was written. Its respect for truth, combined with a far-reaching 
skepticism about what conventionally passed for it, was one of the most 
exciting features of the new work. 

Equally exciting, especially in the articles written by Diderot, was a cer 
tain quality of self-revelation, an air of making the reader a confidant and 
sharing with him literary and scientific judgments, an air both attractive 
and piquant which gave a suspenseful sense of the unexpected. These un 
conventional qualities stirred the wrath of the bigoted, the scorn of the 
pedantic, and the interest of the unprejudiced. The reader of the first volume 
might notice in the frequent articles devoted to cooking inferential evidence 
that Diderot was fond of the pleasures of the table. 27 There, too, he dis 
played his familiarity with the cutler s craft by writing a considerable 
article (Affiler) on the art of whetting knives and bringing lancets to a 
fine edge. 28 It was like Diderot to describe three or four methods for catching 
fish-worms (Achees), to use his columns for paying compliments to Reaumur 
and Frederick the Great, or to include rhetorical bits though quite repre 
sentative of his considered views like those in the article on Alecto, 
whose name corresponds to that of Envy. . . . what envious person would 
not be horrified at himself when he hears it said that Envy is one of the 
three Furies, and that she is the daughter of Hell and of Night . . . what 
could be likely to make virtue more attractive and vice odious . . . ? 29 
Such editorial policies generated some of the curiosity excited by a modern 
syndicated column. It cannot be denied that part of the interest inspired 
by the work arose from a desire to see what the authors would say next. The 
Encyclopedic was edited with a flair for showmanship. 


It was also inspired by an eagerness for improvement and a passion for 
amelioration. About the last thing that could be said about the Encyclopedic 
was that it was content with things as they were. In the largest sense, it had 
a. revolutionary attitude. But the expression of this desire for improvement 
was not limited to cautious verbalizations about religion and matters of 
state: it shone forth in the desire for all sorts of betterments and changes; 
in suggestions, for example, for reforming the alphabet as well as the orthog 
raphy of the French language, or these happen to be suggestions in articles 
written by Diderot himself for more effective methods of agriculture, for 
better techniques of making steel, for the abolition of monopolies, and for 
closer supervision of midwives. 30 This sense of immersion in the circum 
stances of real life not unnaturally constituted for readers of the Encyclopedic 
one of its principal sources of interest. A sample of what Diderot wrote 
about monopolies in the very interesting article on the manufacture of 
needles is representative: 

. . . but it seems to me that there is only one contingency as a result of which ex 
clusive privileges may be accorded without injustice. This is when they are asked 
for by the inventor of a useful article. ... to accord to a company the exclusive 
privilege of making a product that many people are able to manufacture is tanta 
mount to willing that this product, instead of being perfected, should continuously 
become worse and always be sold more dear. 31 

And under the heading of Accoucheuse, Diderot called attention to cur 
rent abuses practiced by midwives who gave instruction in their profession. 
. . . I saw there examples of inhumanity [which he described] that would 
be almost unbelievable had they occurred among barbarians. . . . There 
fore I invite those who are charged with taking care of the disorders that 
occur in society to keep their eyes on this one. 5 32 

Remarks like these, well-intentioned though they were, were apt to be 
regarded as coming close to trenching upon the arcana of authority in gen 
eral and the prerogative of the police power in particular. Diderot was of a 
temperament that could scarcely refrain from telling the political and re 
ligious authorities what their policies ought to be, nor could he have avoided, 
even had he desired, treating in some aspect or other of the Encyclopedic 
these two subjects that were the riskiest and touchiest of all In the France 
of the eighteenth century, Church and State did not regard themselves as 
answerable in any way to the criticism of private persons, nor were they 
likely to consider the public discussion of public matters as even permissible. 


Since the police power was of course all on their side, persons who felt 
inspired to say something on religion or government had to take either 
devious indirections or serious risks. Diderot took both. 

It might be supposed that somewhere in the Encyclopedic would be found 
a plea for freedom in the expression of thought. And so there was, in an 
article written by Diderot about an obscure Roman divinity, Aius Locutius, 
the god of speech. In this unobtrusive corner Diderot wrote eloquently in 
favor of freedom of thought. But the caution that he had to exercise in 
daring to canvass such a view is demonstrated by the curious limitation that 
he voluntarily proposed. Let criticisms of the Church and the government 
be published in a learned language only. If they should happen to be trans 
lated into the vernacular, arrest and punish the translator. Thus freedom 
of thought could be reconciled with the respect due to a people s faith and 
to the national cult. 33 To a twentieth-century reader this proposal seems 
shockingly undemocratic and illiberal, but to the eighteenth century, as 
many criticisms of the Encyclopedic show, it seemed shockingly radical. 

In his article on Political Authority/ Diderot stated his opinions very 
plainly, thereby incurring so much criticism and coming, it is said, so close 
to having the work s license taken away, that for some time thereafter he 
refrained from expressing himself quite so unambiguously. This article 
did indeed sound like one by John Locke or Thomas Jefferson. No man/ 
he wrote, has received from nature the right of commanding others. Liberty 
is a present from Heaven, and every individual of the same species has the 
right to enjoy it as soon as he enjoys reason. . . . 

Tower acquired by violence is only a usurpation, and lasts only as long 
as the force of him who commands prevails over that of those who obey, 
in such a fashion that if these latter become in their turn stronger and shake 
off their yoke, they do so with as much right and justice as did the former 
who had imposed it upon them. The same law that made the authority, 
unmakes it: it is the law of the stronger. 

Therefore true and legitimate power necessarily has limits. . . . The 
prince holds from his subjects themselves the authority that he has over 
them; and this authority is limited by the laws of nature and of state. . . . 
Besides, the government, although hereditary in a family and placed in the 
hands of a single individual, is not a piece of private property, but is public 
property, which in consequence can never be wrested from the people, to 
whom alone it belongs essentially and in full ownership. ... It is not the 
state which belongs to the prince, but rather the prince who belongs to the 


state; but it pertains to the prince to govern the state, because the state has 
chosen him for that, because he has engaged himself toward the people for 
the administration of affairs, and because these, for their part, have engaged 
themselves to obey him conformably to the laws/ 34 

This was stout doctrine, especially during a reign in which Louis XV 
was to tell a delegation of judges, I am your master, I intend to be obeyed. 
I am aware of all the rights that I hold from God, It belongs to none of my 
subjects to limit them or decide the extent of them. 35 The Encyclopedic did 
not indulge very frequently in libertarian essays on the sources of political 
power, although this article on Authority, another by Diderot on Natural 
Law* (Droit naturel), and a later one by Jean-Jacques Rousseau on Economic 
politique in which there appears for the first time in his writings the 
famous concept of the general will prove that it did so often enough to 
keep both friend and enemy on the alert. 

Both friend and enemy eagerly turned to the first volume to learn what 
the Encyclopedic would say concerning the manifold matters relating to 
religious faith. The subject was quite inescapable. On the one hand, there 
existed an elaborate and established system of authoritarian faith, constantly 
manifesting an extreme sensitivity to anything that could be construed as 
inimical to it. And on the other hand there was the pressure of a growing 
scientific and positivistic movement, represented by the Encyclopedic, which 
sought the freedom to search for truth even at the cost of modifying or 
unsettling accepted articles of faith. What was occurring at that time was 
like the uproar and turmoil that took place in the nineteenth century over 
the higher criticism and the concept of evolution. To translate the struggle 
into the idiom of a later time, the Encyclopedists were contending with 
fundamentalists. This aspect of the contest between them is admirably 
illustrated by a contemporary anecdote, even though the incident con 
cerned Swedish Lutherans rather than Roman Catholic Frenchmen. One 
day in the eighteenth century, some Swedish scientists discovered a certain 
alteration in the shores of the Baltic. Immediately the theologians of Stock 
holm made representations to the government that "this remark of the 
Swedish scientists, not being consistent with Genesis, must be condemned." 
To whom reply was made that God had made both the Baltic and Genesis, 
and that, if there was any contradiction between the two works, the error 
must lie in the copies that we have of the book, rather than in the Baltic 
Sea, of which we have the original/ 36 In France there was no one with 
enough authority to speak to the clergy or their defenders in such terms, 
with the result that persons of the stripe of Diderot had to live under much 


the same apprehensions as that o a teacher in Tennessee attempting, about 
the time of the famous evolution trial; to do what he could to impart 
scientific biological knowledge. 

Since persons combating religious authoritarianism could never attack 
their adversary outright and stay out of prison or continue to enjoy 
the right to publish the contest became one of wits. The Encyclopedic 
is a subtle work, written, as Diderot himself declared, to discredit prejudices 
adroitly/ often concealing or almost concealing its real opinions, and pru- 
dentially conveying with a wink and a nudge what it did not dare to say 
aloud. 37 Diderot s attack on the illiberality of religious belief was set forth 
in the Encyclopedic under several guises, and to detect his various devices 
must have been as entertaining to his partisans as it was infuriating to his 
opponents. For example, the Encyclopedic contained frequent appeals to 
reason, though not without a certain air of smugness, implying that the 
writer already had all of it. Thus Diderot wrote, in an article defining to 
adore : The manner of adoring the true God ought never to deviate from 
reason, because God is the author of reason, and because He has desired 
it to be used even in the judgments of what is suitable to do or not to do 
in respect to Him. 88 

A favorite contrivance of the Encyclopedists was to expose, in all their 
multitudinousness, the various heresies of the Christian Church. This was 
a trick they had learned from Bayle. Their descriptions, as Diderot s of 
the Agonyclytes heretics of the seventh century, whose maxim it was 
never to pray on their knees, but standing up 39 were written impas 
sively but not without a certain trace of unctuousness. Combined with the 
somewhat elaborate and ostentatious arrayal of the astonishing variety of 
belief that had occurred in the history of the Christian Church was a con 
stant, undoubtedly sincere, and extremely characteristic appeal for tolera 
tion and broad-mindedness on theological subjects. This was the Enlighten 
ment seeking to discredit scholastic discussion and religious dispute. Diderot 
wrote a typical example of this sort of appeal in an article on a Mohammedan 
sect: 40 Furthermore, I shall observe that the concurrence of God, His 
providence, His prescience, predestination, liberty, occasion disputes and 
heresies wherever they are discussed, and that Christians would do well 
in these difficult questions, says M. d Herbelot in his Bibliotheque orientate, 
to seek to instruct one another peaceably, if that be possible, and to tolerate 
one another charitably on those occasions where they are of different senti 
ments. Indeed, what do we know of such matters? Quis consiliarius ejus 
juit? * 

* Who was the authority for it? 


Another device used by the Encyclopedic was the castigation of certain 
ancient pagan practices that, in reality, had close and obvious Christian 
analogues. Partly this technique bespoke an intellectual deficiency on the part 
of the philosofhes in that they showed little understanding of the religious im 
pulse in man s psychological nature, little realization that they were by way of 
building a kind of church of their own. Moreover, their scorn for all re 
ligious institutions, whether primitive or advanced, reveals to a twentieth- 
century reader that the sciences of anthropology, comparative religion, and 
sociology were then only embryonic. It cannot be denied, however, that the 
philosofhes drew great advantage from what was essentially a propaganda 
device: no devout Christian could take them to task for heaping scorn on 
pagan customs. And so Diderot wrote, for example, of the eagle, in an 
article which was far from being ornithological: The eagle may be seen 
in the images of Jupiter, sometimes at his feet, sometimes at his side, and 
almost always carrying a thunderbolt in his talons. There is every appear 
ance that this whole fable is founded simply upon observing the flight of 
the eagle, who loves to soar in the loftiest clouds and abide in the realm of 
the thunderbolts. That was all that was necessary to make it the bird of 
the god of heaven and the air, and give it a thunderbolt to carry. One had 
only to get the Pagans started when their gods were to be honored: rather 
than remain at rest, superstition conjures up the most gross and extravagant 
visions. Then these visions become consecrated by time and by the credulity 
of peoples; and woe to him who, without being bidden by God to the 
great and perilous calling of a missionary, loves his repose so little and knows 
mankind so ill as to take upon himself to instruct them. If you introduce 
a ray of light into a nest of owls, you will only injure their eyes and excite 
their cries. A hundred times happy are the people bidden by religion to 
believe only true, sublime, and holy things, and to imitate only virtuous 
actions. Such a religion is ours, wherein the Philosopher has only to follow 
his reason in order to arrive at the foot of our altars/ 41 

Thus Diderot ended this article with a pious flourish which the orthodox 
and the nai ve found very edifying, but which the sophisticated presumed 
to be heavily ironical. This practice of saying, somewhat ostentatiously, the 
contrary of what he meant has raised through the years some contention 
as to Diderot s intellectual honesty. Even Voltaire, an expert if ever man 
was in covering his own tracks, was wont to complain that Diderot went 
to quite unnecessary lengths in his willingness to conform. The circumstances 
in which the two men wrote were quite different, however. Voltaire chose 
to live where he could nimbly skip across the border into Geneva when 
trouble threatened. Diderot lived in Paris, and also felt a heavy responsibility 


toward his Parisian publishers, whose fortunes were invested in the venture. 
This situation led to a number of complicated moral problems. Did not 
the stark necessity of bare survival justify an apparent acquiescence in 
orthodoxy? What were the moral rights and obligations of an editor under 
conditions so perilous and adverse? Could a man remain honest and still 
publish orthodox statements in which he had no belief? Were there 
any moral considerations conferring upon him the right to dissimulate his 
real opinions? These were problems Diderot lived with every day of the 
twenty-five years that the Encyclopedic was in preparation, and we find 
him now and again alluding in the Encyclopedic to the hazards of his 
exposed position. In the very first volume, he refers to criticisms of Pliny 
in a situation that is transparently also his own. In the article on Achor, 
the fly-chasing god or god of the flies, Diderot seems to be making a bid 
to his partisans for an understanding of the difficulties of his position. Tliny 
says/ he wrote, that the inhabitants of Gyrene sacrificed to him [Achor], in 
order to obtain deliverance from these insects, which sometimes occasioned 
contagious sicknesses in their country. This author adds that they [the flies] 
died as soon as the sacrifice had been made. A modern scholar remarks 
that Pliny could have contented himself with saying, for the honor of 
truthfulness, that this was the vulgar opinion. As for me, it seems to me that 
one ought not to demand a truth that might be dangerous to express, from 
an author accused of lying on so many occasions in which he would have 
been truthful had it not been for the consequences; and that Pliny, who, 
apparently, hardly believed in the divinity of the god of the flies, but who 
did undertake to instruct us of the prejudice of the inhabitants of Cyrene 
in that regard, could not express himself otherwise without jeopardizing 
his own tranquillity. This is, I believe, one of those occasions when one can 
not draw from an author s testimony any conclusion either against himself 
or for the fact that he attests/ 42 

The Encyclopedic, far from seizing every possible opportunity to fly in 
the face of orthodoxy, frequently seemed to acquiesce in it. But often the 
reasons adduced for believing in a given matter were perfidious, arousing 
more doubts than they allayed. Sometimes a defense can be so extraordinarily 
nerveless and unconvincing that it leaves the reader, as lago left Othello, 
with long and lingering doubts. Nowhere was this technique of the Ency 
clopedic more palpable than in articles in which the literal interpretation 
of the Old Testament was involved. It was not to be expected that the 
Encyclopedic would ever put itself into the position of flatly contradicting 
what was officially regarded as the revealed word of God, but by the pro- 


liferation of common-sense considerations or by the confusing juxtaposition 
of erudite, orthodox, and mutually contradictory authorities, it managed 
to stir up doubts. Nor was this sort of attack gratuitous or without justifica 
tion. The battle over fundamentalism in the nineteenth century suggests 
that the leaders of the Enlightenment a century earlier were not mistaken 
in feeling that the infant biological and social sciences were fighting for 
breath and life against the suffocation that comes from a belief in the 
literal truth of the Book of Genesis. Had the Roman Catholic Church of 
two hundred years ago regarded scientific inquiry in the spirit of Pope 
Pius XII s address to the Pontifical Academy of Science in 1951, conditions 
would have been profoundly different. The scientists and social scientists 
of 1751 would not then have experienced the sense of intellectual strangula 
tion that they did. 

The Encyclopedic, of course, did not invent the technique of casting 
rationalistic doubts upon the Old Testament. That mine had been opened 
by Spinoza in his Tractatus tfieologico-politicus (1670) and had been in 
dustriously exploited by the English deists. Voltaire found many a nugget 
there, and the Encyclopedic, too, made many profitable trips to the pit head. 
One of the most interesting was the article in the first volume concerning 
Noah s Ark (Arche de Noe}, an article contributed by the Abbe Mallet. 43 
With a very grave countenance and the mien of a person dancing a stately 
pavanc, the Abbe set forth what the best authorities had conjectured con 
cerning the time it had taken to build so large an edifice, especially considering 
that the Scriptures say that only four persons ever worked upon it; what 
must have been their strength, considering the size of the timbers needed; 
how many species of animals had to be provided for, making extrapolation 
for all those species not even yet known to Europeans; the dimensions 
and internal arrangement of the Ark, the probable number of decks, the 
amount of fodder needed, the disposition of weight to prevent tipping, 
storage space for fodder and fresh water, arrangements for cleaning and 
ventilating the animals stalls, and the probable minimum number of the 
same; provisions for an extra number of lambs for food for the carnivorous 
animals; the possibility of a fish reservoir for the food supply of amphibious 
animals and birds, etc. By the time the Abbe laid down his pen it was 
evident that a considerable number of common-sense problems are pre 
sented by Noah s Ark. But, as Diderot remarked elsewhere in Volume I, 
the word of God, who explained Himself positively concerning these 
important matters, leaves no place for hypotheses. 44 


The several devices that Diderot and his collaborators employed to stimulate 
merest in the Encyclopedic were frequently combined in a single article, 
vfany contributions that purport to be summaries of existing knowledge on 
rertain subjects actually are vibrating and resonant with overtones of the 
enlightenment. Let one very good sample suffice in illustration: the sup 
plementary article, six columns in length, that Diderot wrote on Ame 
(Soul or Mind). The principal article on this tricky and touchy subject 
was treated by the Abbe Yvon in a conventional and innocuous manner. 
What Diderot did in addition was to speculate where in the body the dmc 
resided; to show by his numerous references and citations that he was fully 
informed about current scientific investigations on the subject; to point 
out the close connection between soul and body, so that a disarrangement 
of a nerve fiber can bring on mental illness; to proffer some advice on child 
care; to give some interesting and specific case histories, one of which cor 
related religious hysteria with physical disease; and to end the whole by 
posing a problem bearing upon both aesthetics and psychopathology, namely 
whether painting has as much influence on the soul as music! 

This was the sort of approach that opened windows and broadened hori 
zons. Yet to the orthodox and conventional in matters of religion, any 
discussion of the soul that suggested any organic connection with the body 
was likely to seem vaguely impious and somehow impudent. Nevertheless 
the progress of knowledge indubitably required exploration of this very 
relationship. The problem was unfortunately and unnecessarily embittered 
by an accident of language: the French word dme means both soul and 
mind. 45 It is the portal word, the junction point, for both theology and 
science, for both metaphysics and psychology. Probably the intellectual 
crisis of the eighteenth century in France would not have engendered such 
bitterness had men been able to talk of the mind without theologians sup 
posing that they were talking of the soul. Perhaps the growth of science in 
the eighteenth century, for which the Encyclopedic and Diderot fought so 
fiercely, would not have had to take a turn so aggressively anticlerical had 
the philosophes been able to talk of psychology, neurology, and psycho- 
pathology in other words, of the mind without being suspected of de 
siring to attack or demolish the concept of the soul. Perhaps the milder and 
less embittered form that the Enlightenment took in the English-speaking 
world was owing to nothing more than the fact that the English language 
has a word for each. No wonder Diderot often revealed an awareness of the 
problem of semantics. 

The idea that the mind and the body, or the soul and the body, are bound 


together in close and reciprocal relationship would seem to be nothing but 
common sense. Yet in Diderot s day one had to be exceedingly careful what 
one said on this subject, lest one be traduced as a materialist and an atheist. 
Nevertheless this is a concept absolutely basic for the scientific understand 
ing of mental disease, just as it is also the foundation of all neurological 
studies and of psychosomatic medicine. Diderot s most daring writings on 
this subject, such as D Alembert s Dream, were much too dangerous to be 
published during his lifetime. But in the Encyclopedic he wrote what he 
could, never being one to fail to recognize an issue of importance or to 
avoid discussing it as much as was possible. Let us consider, he wrote in 
his supplementary article on the Ame c on what small things depend the 
functioning of the Ame: a fiber out of order, a drop of extravasated blood, 
a slight inflammation, a fall, a contusion: and farewell to judgment, reason, 
and all that sagacity of which men are so vain. All this vanity depends upon 
a filament well or poorly placed, healthy or unhealthy. 46 


The Encyclopedic was a great reference book, a great repository of knowl 
edge. But it was more than that, by far. The Encyclopedia conveyed to its 
readers a stimulus that was frequently as much emotional as it was intel 
lectual. Consequently, the terms used to describe the Encyclopedic^ effect 
should not convey simply passive images. The words descriptive of it should 
be active. It was a detergent, a tool with a cutting edge, a window opener. 
It was something that one could learn to use for the performance of tasks 
one was insufficiently equipped to do before. And because this was so, it 
was unavoidable that the Encyclopedic and its principal editors were destined 
to figure conspicuously in the history and politics of the eighteenth century. 


Up till Now, Hell Has Vomited Its 
Venom Drop by Drop 

Y THE time that Volume I of the Encyclopedic 
was finally published on 28 June 1751, public 
interest had been whetted to a sharp edge of expectation. There had been 
the two prospectuses, the one of 1745 as well as the more elaborate one in 
1750; there had been the preliminary publication of sample articles, Diderot s 
on Art and the naturalist Daubenton s on Bee (Abeille) and Agate 1 
that on the bee to show that the Encyclopedic would be an indispensable 
repository of information already acquired, the one on agate to show how 
it would include information entirely new and unavailable elsewhere; and 
gaining the most public attention of all, there had been the hot-tempered 
exchange between Diderot and Father Berthier of the Journal de Trevoux. 
In addition, Diderot s previous publications, both the salacious and the rad 
ical, had indicated that his editing would be anything but colorless, so that 
potential friends of the new work counted upon finding their best hopes, 
potential enemies their worst fears, fully confirmed. 

The excellence of the Encyclopedic was attested by attempts of foreigners 
to pirate it. Only a few months after the publication of the first volume 
the publishers became aware that they were being paid this sincerest kind 
of flattery. A syndicate of English publishers, hoisting the Jolly Roger, pre 
fixed to their translation of the Preliminary Discourse and its accompany 
ing documents the announcement that the Proprietors have engaged in a 
Design of reprinting the Whole at London, with a View to serve their 
Country, by encouraging Arts, Manufactures, and Trades; and keeping large 
Sums at Home, that would otherwise be sent Abroad. They offer their 
Work at Half the Price of the Paris Edition; and hereby promise, in case 
they meet with no Discouragement, to proceed regularly in printing the 



subsequent Volumes/ 2 To head oft this threat, the French publishers author 
ized Briasson and David to go to London to treat with the English book 
sellers and offer them copies of the French edition at very low cost. The 
Frenchmen made this journey in November and entered into an agreement, 
the details of which are obscure but which was ratified by their partners in 
February ij^i. 5 This is the last heard of this particular venture in piracy. 
Still another English translation was proposed at about the same time, this 
one by a Sir Joseph AylofEe. Apparently the French publishers did nothing 
about it, and AyloflEe s project, which appeared in weekly installments be 
ginning on ii January 1752 and costing six pence each, seems never to have 
proceeded beyond the eighth installment. 4 

The publication of the first volume of the Encyclopedic made it the focus 
of discussion in Paris. It had both censors and partisans, remarked Raynal, 
who added that both were in the right, for the work was blameworthy for 
the useless subjects included and praiseworthy because of its philosophic 
spirit. 5 The statement of the journalist Clement of Geneva, expressed in 
his news letter of 15 August 1751, also reveals the volume s somewhat mixed 
reception: You have remarked, Monsieur, that with his vagrant as well 
as scientific imagination, M. Diderot would inundate us with words and 
sentences. This is the complaint of the public against his first volume, which 
appeared a little while ago. But an infinitely copious background of material 
and a fine taste for sound philosophy, which gives value to it, compensate 
for all these superfluities. 6 Intellectual snobs complained that the Encyclo 
pedic was a short-cut to culture, 7 a view rather frequently expressed as this 
typical epigram shows: 

Well, here we have the Encyclopedic, 
What luck for the ignorant! 
How this learned rhapsody 
Will hatch out false savants! * 

A little later Raynal remarked that one often finds in the Encyclopedic what 
one is not looking for, and often searches fruitlessly for what one wants. 
Several of the authors write in a barbarous style, several in a precious manner, 
and many possess nothing but prolixity. Still later he wrote that the first 
volume of the Encyclopedic, which at first succeeded very well, is quite gen 
erally scoffed at. One sees such revolutions only in France. 8 

* Voici done YEncy clop die; 
Quel bonhcur pour Ics ignorants! 
Que cette doctc rapsodie 
Fcra naitrc dc faux savants I 


The evidence of an increasing subscription list proves that Raynal was 
exaggerating. Le Breton was printing an edition of 2,075 in place of the 
1,625 originally planned. 9 Yet criticism did exist, symbolized by a rather 
ominous epigram which D Hemery picked up and recorded in his journal: 10 

Je suis bon encyclopediste, 
Je connais le mal et le bien. 
Je suis Diderot a la piste; 
Je connais tout, je ne crois rien.* 

The first rumblings of the attack came in the September columns of the 
influential Journal des Sgavans, and greatly upset D Alembert. The Journal 
praised the Preliminary Discourse/ but Ve are obliged to warn that this 
work has its defects. . . . The author supposes that sensations alone con 
stitute the origin of ideas, . . . The system of Locke is dangerous for re 
ligion, although one has no objections to make when those who adopt it 
do not draw noxious conclusions from it. M. d Alembert is of this number; 
he recognizes rather eloquently the spirituality of die soul and the existence 
of God, but he is so brief on each of these subjects, concerning which there 
are so many things to say, and he is so copious on others that the reader has 
a right to demand the reason for the distinction. . . . 

One might suspect this Preface of an affected laconism in respect to re 
ligion. 11 

Much more trouble was made by the Journal de Trevoux. The animad 
versions of these Jesuits proceeded in a crescendo. Their first review, sour 
and grudging, appeared in the issue for October 1751. D Alembert had 
spoken in the Preliminary Discourse of those pedantic puerilities honored 
by the name of Rhetoric/ and the Jesuits evidently felt that this shaft had 
been aimed directly at them, rhetoric being so important a part of the educa 
tion they dispensed to Europe. (They also took some of Diderot s remarks 
in his article on Aristotelianism as intended to disparage them.) 12 This 
made them captious. When D Alembert remarked that Pope Zacharias had 
rebuked a bishop, they pointed out peevishly that it wasn t a bishop, it was 
a priest. When D Alembert praised Voltaire for writing good prose, the 
Journal pettishly remarked that other poets were known to have written good 
prose, too. But the Journal was on firmer ground when it called attention 

* I am a good Encyclopedist, 
I know both good and evil. 
I follow hot on Diderot s trail; 
I know everything and believe in nothing. 


to various editorial and typographical slips, especially to the frequent failure 
of the Encyclopedic to give adequate credit to its sources. 18 

Month after month, the Journal de Trevoux returned to the attack. 14 In 
November it complained of the Encyclopedias policy of excluding history 
and biography from its articles. The names of kings, savants, saints, etc., 
are excluded from the Encyclopedic, yet those of pagan divinities are ad 
mitted, and this occurs not only for gods of the first order, such, for example, 
as Amphitrite, Anubis, Apis, Apollo, Astraea, etc., but also for those of the 
second or third rank, such as Abellio, Achor, Acratus, Adephagie, Adramelech, 
Aius Locutius, and a multitude of others. 1 The last named article, in which 
Diderot had pleaded for the free expression of ideas provided they were 
written in a learned language, presumably Latin, profoundly shocked the 
editors of the Journal de Trevoux as being contrary to the tranquillity of 
the state and religion. It was transparent that the editors felt that if ever there 
was an instance of liberty seeking to become license, this was it. The first 
volume of the Encyclopedic, they said ominously, showed no vestige of 
having been submitted to the customary censorship. 15 A remark such as this 
must have warned the editors of the Encyclopedie that their project was 
under ruthless and unscrupulous attack, for the volume had been submitted 
to the censors, as we have seen, and one of the most respected theologians 
of France, the Abbe Tamponnet, a former syndic of the Sorbonne, had 
certified on 15 March 1751 that by order of My Lord the Chancellor I 
have read the portion of the Encyclopedie concerning theology and eccle 
siastical history, in which I have found nothing contrary to sound doctrine.* 16 

In attempting to undercut the prestige of the Encyclopedic, the Journal 
de Trevoux developed very effectively the technique of identifying and ex 
posing plagiarisms. A little plagiarism goes a long way in discrediting a 
book s claim to originality, even though the vast mass of the work be new, 
and the editors of the Journal de Trevoux, with their talent for polemical 
in-fighting, naturally struck the Encyclopedie precisely where it hurt the 
most. 17 Unacknowledged borrowings were all too common in the Encyclo 
pedie. It is true, although rather beside the point, that in spite of them the 
Encyclopedie was a work of great utility. This, in fact, the Journal de 
Trevoux cheerfully acknowledged, especially with regard to the arts and 
crafts. One may pillage the way the bees do/ wrote the Journal de Trevoux, 
carefully acknowledging their source, without doing anybody wrong, but 
the thievery of the ant, which walks off with the whole thing, ought never 
to be imitated. 18 Indeed, these strictures were so devastating that Diderot 


and D Alembert felt the necessity of inserting an explanation in the preface 
to their second volume. 19 

Besides dilating upon the matter of plagiarism, the Journal de Jrevoux 
took very great exception to the article that Diderot wrote on Authority. 
It took equally great offense at a remark by the Abbe* Yvon that most men 
honor letters as they do religion and virtue, that is to say, as a matter that 
they do not choose either to understand or practice or love/ 21 After three 
pages of comment set off by this fuse, the Journal concluded by saying, 
This is sufficient concerning this article which alarms (we happen to 
know) people of merit and which deserves the greatest attention on the 
part of the authors and editors of the Encyclopedic in order that henceforth 
nothing else of the sort creeps into it/ 22 In general, the attitude of the 
Journal dc Trevoux might be described as touched with condescension: 
These reflections/ wrote the editor, are not intended to wound the authors 
of the great Dictionary. As the work advances, no doubt it will acquire a 
greater perfection; and we shall review it with an equal degree of care and 

impartiality. 23 

Disagreeable as the Journal de Trevoux was making itself, its strictures 
were nevertheless scarcely influential enough by themselves to be catastrophic. 
Serious trouble did supervene, however, when, in addition to having to 
weather the attacks of the Journal de Trevoux, the Encyclopedic found itself 
involved in the celebrated scandal of the thesis of the Abbe de Prades, an 
episode that has been called the culminating point of the religious history 
of the eighteenth century. 24 

On 18 November 1751 the Abbe Jean-Martin de Prades triumphantly de 
fended during a ten-hour public examination *ab octavd matutind ad 
sextem vespertinam, ran the posted thesis announcing the event a the 
ological thesis qualifying him for the licentiate in the theological faculty 
of die University of Paris. This was an advanced degree for which he had 
been several years in preparation, and for which he had satisfied all the 
usual requirements, such as securing the necessary approval of various 
Sorbonne doctors and officials before printing his thesis. Entitled Jerusalem 
coelesti, it was published in an edition of 450 copies and had been publicly 
posted for the statutory length of time before the public examination in the 
usual form of such theses, printed on extremely heavy paper, elephant folio 
size, on a single sheet. A considerable collection of these theses, De Prades s 
among them, may be seen today at the Bibliotheque Nationale in Paris. 25 
Usually decorated with an engraving of a scene depicting a religious subject 
or suggesting religious awe, the theses, most of which were quite short, 


usually fitted readily into the single-page format. De Prades s thesis was 
considerably longer than the ordinary, approximately eight thousand words, 
so it was printed in extremely small type. 

Indeed, the type was so small that apparently no one took the trouble to 
read it, including the reverend professor of theology, an Irishman named 
Luke Joseph Hooke, whose special and particular responsibility it was. The 
Abbe de Prades sailed through his examination triumphantly, and not until 
some days afterward did rumors begin to fly that the Sorbonne had solemnly 
placed its seal of approval upon a thesis that was later characterized by formal 
censure of the Sorbonne itself as blasphemous, heretical, erroneous, favorable 
to materialism, contrary to the authority and integrality of the laws of 
Moses, subversive of the foundations of the Christian religion, and impiously 
calling into question the veridity and divinity of the miracles of Jesus Christ. 26 
Thereupon everyone began to read the small print. What everyone found 
in this dissertation, which purported to summarize all the arguments in 
proof of Christian revelation, was something that closely followed the 
psychological doctrines, and even their manner of presentation, in D Alem- 
bert s Preliminary Discourse. 27 De Prades further argued that any faith 
that preserves the natural law in all its purity is preferable to any re 
vealed religion except, of course, the only true one. This was an argument 
practically identical with Diderot s in his manuscript work On the Suf 
ficiency of Natural Religion. 2S In other portions of his thesis De Prades 
expounded the fact that three different systems of chronology are to be 
found in the Pentateuch, from which he concluded that Moses had had 
nothing to do with any of them; and then the candidate proceeded to examine 
the nature of the proof requisite for a belief in miracles. He ended by de 
claring that the healings performed by Jesus Christ were similar in a 
number of respects to those performed by Aesculapius! 29 

The only plausible reason explaining why De Prades was able to pass an 
examination in defense of such propositions is that there must have been 
in the Sorbonne a number of ecclesiastics who were not yet opposed to 
the new philosophy 1 and the intellectual methods it entailed. 80 It is pre 
cisely for this reason that the incident is important in the intellectual history 
of the eighteenth century, for after this the lines were sharply drawn. 
^Nothing is better calculated/ wrote a pamphleteer just at this time, for 
making obvious the danger of the system that places the origin of our ideas 
in the impression of the senses than does the use that the enemies of Re 
ligion make of it. Doubtless because it has been regarded as merely a phil 
osophical opinion, there has been no alarm over the favor gained by this 



system, even in the Schools of the University, during the past few years. But 
the impious thesis of Monsieur de Prades has finally opened people s eyes 
concerning the disturbing consequences that result from it/ 31 

The Sorbonne now found itself in an extremely embarrassing position, 
for if ever there was an institution in the ancien regime expected to be 
vigilant in the protection of orthodoxy, it was the faculty of theology of 
the University of Paris. Reproached by its friends and mocked by its enemies, 
it was in the mortifying position of an armed service that discovers that 
its most famous battleship has, in a moment of negligence, gone aground. 

The result, usual in such circumstances, was a search for scapegoats. A 
Sorbonne committee proposed on 3 January 1752 that ten propositions set 
forth in the thesis be censured. There then followed eleven general assemblies 
of the Sorbonne, during which no less than 146 doctors were present, 
according to one authority; delivered speeches, according to another. 32 It 
developed that the unfortunate Hooke had approved De Prades s thesis 
without reading it, being much preoccupied at that moment with correcting 
the proofs of a book of his own! 33 Hooke lost his chair. De Prades s thesis 
was condemned by the Sorbonne, as well as by the Archbishop of Paris 
and the Pope. 34 The comments of the Bishop of Montauban, to whose juris 
diction De Prades was responsible, were particularly comprehensive. Up 
till now/ he wrote in a pastoral charge, Hell has vomited its venom, so to 
speak, drop by drop. Today there are torrents of errors and impieties which 
tend toward nothing less than the submerging of Faith, Religion, Virtues, 
the Church, Subordination, the Laws, and Reason. Past centuries have wit 
nessed the birth of sects that, while attacking some Dogmas, have respected 
a great number of them; it was reserved to ours to see impiety forming a 
system that overturns all of them at one and the same time. 35 De Prades 
fled to Berlin, in order to escape the warrant for his arrest, and there became 
reader to Frederick the Great. Some years later, he recanted and made his 
peace with the Church. 

Meanwhile it began to be alleged that the whole imbroglio was simply 
the result of a conspiracy on the part of the editors of the Encyclopedic, a 
plot to overturn religion. Even the Jansenists, who regarded both the philo- 
sophes and the Sorbonne with equal malevolence, remarked in their under 
ground newspaper, Les Nouvelks EccUsiastiques, that the stir caused by the 
thesis has occasioned the discovery through different circumstances and by 
certain facts that the thesis of M. de Prades was the result of a conspiracy 
formed by some would-be freethinkers in order to insinuate their monstrous 
errors into the Faculty of Theology and moreover to make more conspicuous, 


if possible, the irreligion and impiety that they affect/ 36 The same allegation 
was made in a pamphlet entitled Reflexions d un Franciscain, which, though 
it had a frontispiece representing Diderot being flogged by a Franciscan, 
probably was not written by a Franciscan at all. 37 Diderot, in his article 
on Aristotelianism, had provocatively declared that Duns Scotus, the famous 
Franciscan theologian, made his merit consist in contradicting Saint Thomas 
Aquinas in every respect; one finds in him nothing but vain subtleties and 
a system of metaphysics rejected by everyone with common sense. 38 It is 
not surprising that some sort of counterattack in answer to this should soon 
appear in the name of the Franciscans. The Reflexions d un Franciscain, if 
we may believe D Hemery, who referred to the pamphlet in his journal 
entry for 20 January 1752, was really written by Father Geoffroy, a Jesuit 
professor of rhetoric at the order s famed College Louis-le-Grand. 39 Here 
we see once again how the Jesuits took the lead in attacking the Encyclopedic. 
The pamphlet pointed out that De Prades lodged under the same roof with 
two priests associated with the Encyclopedic [the Abbes Yvon and Mallet], 
that he was a contributor to it himself, and that among his colleagues on the 
Encyclopedic were several quite capable of writing such a thesis. 40 More 
over, the Franciscan contended that earlier theses by De Prades could not 
compare in Latinity or intellectual competence with the Jerusalem coelesti^ 
It was regarded as a particularly suspicious circumstance that the Pre 
liminary Discourse of Volume I had spoken in high praise of a forthcoming 
work by De Prades on religion, although in reality there is nothing to 
show that it was De Prades s thesis that D Alembert had had in mind. 42 
Moreover, the Abbe was the acknowledged author of the long and important 
article in Volume II of the Encyclopedic on Certitude. This article, prob 
ably written by De Prades in good faith, explored searchingly the logical and 
historical grounds for believing testimony regarding miracles, especially that 
of the Scriptures in general and of the Resurrection in particular. It was 
a sober and ingenious piece of work, but it must be admitted that while it 
claimed to deepen faith, it could scarcely have done so save in the case 
of persons already determined to believe. Since Volume II saw the light in 
late January 1752 (even though the title page bears the date 1751), just at 
the time of the greatest uproar over De Prades s thesis, it was easy to portray 
the whole concatenation of incidents as nothing but the ramifications of 
an Encyclopedist plot. 43 

What is the evidence for this persistent and frequently stated suspicion? 
All of it is circumstantial and inconclusive. In their most extreme form, the 
allegations insinuate that De Prades was mentally incompetent and simply 


allowed himself to be a sort of ventriloquist s dummy for D Alembert and 
Diderot. This can hardly be, for De Prades sustained a long and searching 
oral examination upon his thesis, a feat that requires both previous prepara 
tion and mental adaptability. There is no evidence that D Alembert or 
Diderot wrote all or any part of De Prades s thesis for him, although there 
is a good deal of testimony to the effect that the Abbe Yvon did. 44 According 
to Naigeon, Diderot played no part in it except for the counsel he gave 
the two authors to leave the usual highway a little to one side and to make 
the hardened ears of the doctors listen now and again to the language of 
reason. 45 Nor should it be forgotten that in their preface to Volume III 
of the Encyclopedic, Diderot and D Alembert asserted that we had not 
even read [the thesis] at the time when people were making use of it in the 
effort to ruin us/ 46 

Or, if it was not insinuated that Diderot and D Alembert wrote or prac 
tically wrote the thesis, the allegations reduced themselves to accusation of 
guilt by association. Association there certainly was. After all, De Prades 
was the contributor of a very important article, and it would be entirely 
natural for a contributor, living in the same city as the editor, to be in 
personal touch with him. 47 This association with the eloquent and crepitating 
Diderot must have had a powerful effect on De Prades. If not, he was the 
first to escape such influence. But association is not the same as conspiracy, 
in spite of many eighteenth- and twentieth-century attempts to equate them. 

This is not to contend that Diderot had no influence on the thesis, only 
that there is no proof that he did. It may even be that Diderot and D Alem 
bert encouraged De Prades to see how far it was possible to go, as a means 
of feeling out public opinion to guide them in their own editing of the 
Encyclopedic. 43 This could be, although to play such a game involved con 
siderable risks, as subsequent events were soon to prove. 

In retrospect this period reveals itself as one of struggle between Diderot 
and the Jesuits, the stakes being, as it frequently came to be said, the editing 
of the Encyclopedic itself. The Jesuits were profoundly suspicious of the 
venture and, indeed, have remained so, as is evidenced by the fact that 
as recently as 1952 a writer in the Jesuit periodical Etudes referred to the 
Encyclopedic as the most formidable machine that ever was set up against 
religion. 49 In 1752 the Jesuits appear to have been determined either to 
capture the Encyclopedic or to destroy it. Such was the interpretation several 
contemporary observers put on the effort to discredit Diderot and the En 
cyclopedic by representing the De Prades affair to be the result of a con 
spiracy. This interpretation of the incident was subscribed to not merely 


by such a weekly news letter as La Bigarure, which might have published 
the charge just for effect, but also by Voltaire, to whom is usually attributed 
the pamphlet called Le Tom beau de la S or bonne. His asseverations, how 
ever, could conceivably be regarded as counterpropaganda, just as could 
those of Grimm, who referred in his confidential news letter to odious con 
spiracies. 50 But the frequent declarations of the diarist Barbier, who wrote 
that this whole storm against this fine Dictionary comes by the medium of 
the Jesuits/ and of D Argenson, the former secretary of state for foreign 
affairs, who asserted that this storm comes from the Jesuits, have all the 
weight due to the conclusions of well-placed persons who, in their con 
fidential diaries, may be presumed to have had no motive for altering what 
they conceived to be the truth. 51 As early as mid-January 1752, D Argenson 
was predicting that the Encyclopedic would be suppressed and that the 
Jesuits would take it over. 62 

Powerful elements at the Court also joined in the fight against the Ency 
clopedic. Their leader was the tutor of the Dauphin, Boyer, the former 
bishop of Mirepoix, a man said to be devoted to the Jesuits. 53 Boyer was 
entrusted with the ecclesiastical patronage of the kingdom and consequently 
was a powerful and influential personage. He took alarm at the De Prades 
incident and linked it with what he regarded as the subversiveness of the 
Encyclopedic. The most ardent enemy of the Encyclopedic, wrote Males- 
herbes, who ought to know, because his position as director of the book 
trade made him the one official to whom complaints of this sort were ad 
dressed in the first instance, was the former bishop of Mirepoix. He carried 
his complaints to the King himself, and said to him with tears in his eyes 
that one could no longer conceal from him that religion was about to be 
ruined in his kingdom/ 64 It is not very surprising, then, that an Arrct du 
Conseil du Roy (7 February 1752) suppressed the further publication, sale, 
and distribution of the Encyclopedic: His Majesty has found that in these 
two volumes a point has been made of inserting several maxims tending to 
destroy the royal authority, to establish a spirit of independence and revolt, 
and, under cover of obscure and ambiguous terminology, to build the founda 
tions of error, of moral corruption, of irreligion, and of unbelief. 55 

For the second time in his life, Diderot found himself involved in the 
public policy of the state. Both incidents, the one leading to Vincennes 
in 1749 and this one, ending in the catastrophe of the suppression of the 
Encyclopedic, were crises in the history of the freedom of thought, making 
Diderot an important figure in the political history of the eighteenth century. 
But it was most uncomfortable to exist in such an exposed position. The 


Encyclopedic had been solemnly and officially described in the royal decree 
as being close to treasonous. By inference its editor had been pilloried in a 
state paper and singled out as a target for public indignation, assailed (to 
use the parlance of American journalism) as Public Enemy No. i. "This 
morning/ wrote D Argenson, appeared an arret du conseil which had not 
been foreseen: it suppressed the Dictionnaire encyclopedique, with some 
appalling allegations, such as revolt against God and the royal authority, 
corruption of morals . . . etc. It is said on this score that the authors of 
this dictionary, of which only two volumes have appeared, consequently 
must shortly be put to death, that there is no way of preventing their being 
hunted down and informed against.* 56 

Diderot came to think, in his later years, that his own compatriots showed 
him less honor than did foreigners. The obloquy of the arr&t du conseil of 
February 1752 could very well have contributed to making this sentiment 
burgeon within him. 


The Encyclopedic Recontinued 


DIDEROT S very person may have been in danger 
during the days following the suppression of the 
Encyclopedic. D Argenson reported on 12 February that it was rumored that 
a lettre de cachet had been issued against him, and supplemented this hearsay 
by the further entry, 25 February, that Diderot had taken flight in order to 
forestall arrest; and Barbier wrote that Diderot was afraid of being put a 
second time into the Bastille. * In reality, there is no evidence from a source 
close to Diderot that he ever left his house in the Rue de 1 Estrapade. Never 
theless this was probably a period of great anxiety and alarm, especially as 
he was forced to surrender what manuscripts he had in preparation for suc 
ceeding volumes. There have been taken away from him all the authors 
manuscripts, as well as from the publishers all remaining copies of the 
first two volumes and twenty-five sheets already printed of the third. 2 Ap 
parently Diderot delivered the manuscripts personally, sometime around 
21 February, either to Malesherbes, the director of publications, or to his 
father, Lamoignon de Blancmesnil, who since 1750 had been D Aguesseau s 
successor as Chancellor of France. 3 

The impounding of the manuscripts was preliminary to the Jesuits* at 
tempting to carry on the work. D Argenson had recorded, a week after the 
suppression, that it is not doubted that the Jesuits will take the enterprise 
over and continue it. . . . Barbier spoke of the Jesuits as having a devoted 
supporter in the person of Chancellor Lamoignon, and, if Grimm may be 
believed, it seems likely that the Jesuits were given a chance to see what 
they could do. Everything had been well concerted/ wrote Grimm a year 
later. The papers had already been taken away from M. Diderot. Thus 
it was that the Jesuits counted upon making away with an encyclopedia 
already completely finished ... by arranging and putting in order articles 
that they believed to be all prepared. But they had forgotten to take away 



from the philosopher his head and genius as well, and to ask him for the 
key to a large number of articles that, far from understanding, they strove 
in vain to make out/ 4 

But all was not lost for Diderot, for through this lengthy crisis he had 
on his side a very powerful friend. This was Chretien-Guillaume de 
Lamoignon de Malesherbes, a member of a very prominent family of lawyers 
and magistrates belonging to that class of the nobility called in the ancien 
regime the noblesse de robe. Since late in 1750, Malesherbes had been serving 
under his father, the Chancellor, as director of publications. He was only 
twenty-nine when he took up this office, in which he continued until 1763. 
During his administration the great battles over the Encyclopedic were 
fought, which almost entirely changed the intellectual complexion of France. 
It was scarcely possible for a man to occupy more of a key position than 
did he as arbiter and umpire during this momentous struggle. 

At the time he took office, Malesherbes was already the presiding judge 
of the cour des aides, one of the tax courts of the ancien regime. This was a 
purchasable office, and the Lamoignon family, in accordance with the prac 
tice of the time, had simply bought it. What was out of the ordinary was 
that the person for whom the post was purchased should happen to be a 
man of intelligence, adequate legal training, and merit. Malesherbes was a 
man of unusual integrity, without any semblance of personal ambition, and 
had a fine sense of the responsibilities of his office along with a transparent 
desire to carry out its duties with justice to all. When unpretentiousness of 
character was being discussed one day at the famous Mme Geoffrin s, Males 
herbes name came up. So many people pretend to have it, said Mme 
Geofirin, but M. de Malesherbes, there s a man who is unpretentiously un 
pretentious/ 5 

Malesherbes policy as director of publications was as simple and straight 
forward as the rest of him. This policy was molded by the fact that he held 
the highest view of the social usefulness of the man of letters, and once 
wrote that in a century in which every citizen can speak to the entire nation 
by means of print, those who have the talent for instructing men or the gift 
of moving them in a word, men of letters are, in the midst of a dis 
persed people, what the orators of Rome and Athens were in the midst 
of a people assembled/ 6 He himself alluded to his motives and policy in 
a letter written to one of the philosophes in 1758: As for what concerns 
me, you know that during many years I occupied myself exclusively with 
literature and lived only in the company of men of letters. When I found 
myself led by unforeseen circumstances and perhaps against my will 


into a different sphere, I desired nothing else so much as to be able to 
render services to those with whom I had passed my life. I thought I had 
found the occasion of doing so when I was put in charge of the book trade, 
since I found myself in a position to procure for them the liberty of writing 
that I had always seen them sigh for, and to free them from many of the 
constraints under which they appeared to groan and of which they con 
tinually complained. I also considered this to be doing a service to the State, 
for this liberty has always seemed to me to have many more advantages than 
drawbacks. 7 Thus Malesherbes brought to the performance of his duties 
the convictions expressed by Milton in Areopagitica. It is unjust and im 
possible to domineer over opinions, wrote Malesherbes, and consequently 
[unjust and impossible] to suppress, garble, or correct the books in which 
they are set forth. 8 Believing as he did that the exchange of ideas was good 
for a society, Malesherbes constantly favored as little repression instead 
of as much as the pressures that played upon him would permit. For this 
reason he granted many tacit permissions to books that could not be given 
the official imprimatur of the Approbation et Privilege du Roi. Such a 
policy, he believed, was necessary in order to keep up with the world: *A 
man, he wrote, who had read only the books that, when published, ap 
peared with the express consent of the government the way the law pre 
scribes, would be behind his contemporaries almost a century. 9 

With these convictions, it is obvious that Malesherbes often found himself 
in the position of defending radical works. The Encyclopedists were mis 
taken in not believing in Providence, wrote a witty historian of their doings, 
for it was manifestly for their sake that Providence gave to Malesherbes 
the direction of the book trade. 10 Yet it must not be supposed that he was 
a prejudiced and one-sided doctrinaire. Very often he revealed himself as 
being more in favor of freedom of the press freedom for both sides than 
the Encyclopedists were themselves. Not infrequently it seemed that what 
the philosophes wanted was not so much freedom as immunity. What they often 
demanded was apparently tantamount to the right to say what they pleased 
when they pleased, plus protection against the counterattacks of their enemies. 
In fact, Malesherbes seems to have been about the only person in eighteenth- 
century France who desired real freedom of the press. But real freedom 
of the press was a reform that had to wait upon the unfolding of portentous 
events. Meanwhile Malesherbes did his job with dignity and skill, respecting 
his office and making others respect it too, resisting undue encroachments 
on his functions by rival agencies in the government, and revealing an almost 
endless willingness to endure patiently the massive and capricious manifesta- 



tions of temperament displayed so frequently and copiously by the selfsame 

men of letters whom he was endeavoring to assist. 

Much later, in 1775, Malesherbes became one of Louis XVI s ministers but, 
too eager for economy and reform to suit the court opinion of his day, he 
felt obliged to resign in the very next year. In 1792-3 he served his monarch 
for the last time: he was Louis XVTs principal lawyer and brilliant defender 
in the trial preceding the King s execution. The Terror had a rejoinder for 
such conspicuous devotion and in 1794 Malesherbes was tried and guillo 
tined. One of the few monuments to be seen today in the enormous and 
echoing Salle des Pas-Perdus in the Palace of Justice in Paris is a statue of 
Malesherbes. It is a fitting recognition of a courageous and honorable man, 
who cast over the declining days of the ancien regime the refulgence of a 
noble soul. 

This was the man of whom one of Diderot s friends wrote that without 
him the Encyclopedic would most likely never have dared to appear/ 11 
In this particular crisis of 1752 Malesherbes had not favored the suppression 
or even the suspension of the Encyclopedic, according to D Argenson, who 
got his information from one of Malesherbes 5 cousins. Instead he had felt 
that it would be sufficient simply to insert some substitute pages for the most 
offending passages. 12 But in this he had been overruled. It was probably 
owing to his influence, however, that the action taken by the King s Council 
only suppressed the first two volumes instead of revoking the license of 
the whole. 13 He may have been maneuvering, thought Barbier, to forestall 
action by the Parlement, which might have been more severe. 14 Considering 
the action the Parlement had taken six years before in having Diderot s 
Pcnsees philosophiques burned by the hangman, Barbier s hypothesis may 
have been correct. 

During 1752 a number of questions regarding the final disposition of the 
Encyclopedic had to be settled. Were the Jesuits going to continue the 
enterprise? (If not, what were the factors preventing them?) If they did not, 
what terms would the government impose upon Diderot and D Alembert 
as a condition of allowing the work to be recontinued? And finally, would 
the latter raise any difficulties in consenting to these terms? 

It is impossible to say why the Jesuits did not take over the Encyclopedic, 
and Grimm s statement that they were incapable is extremely unpersuasive. 
Still, it is the only testimony that we have on this tantalizing subject, leaving 
us in the realm of vague and dubious conjecture. Probably the fate of the 
Encyclopedic was involved in the chronic struggle for power at the French 
court, for Mme de Pompadour, since 1745 the King s mistress, was an enemy 


of the Jesuits, so that by a sort of Euclidean corollary, she was well disposed 
toward the Encyclopedic.^ This very politically minded woman, the mistress 
of a man who usually regarded the affairs of his kingdom as no concern of 
his, was sincerely interested in the arts and somewhat in the sciences. La 
Tour s dazzling pastel of her, first exhibited in the Salon of 1755 and now 
hanging in the Louvre, symbolizes these interests : a portfolio of engravings 
is at her feet, in the background is a guitar resting on a sofa, she holds a 
piece of music in her hands, and on the table by her side are a globe and 
a number of volumes, including a folio on the back of which can be plainly 
read: ENCYCLOPEDIE, TOME IV. 16 D Argenson, evidently on the 
authority of D Alembert, remarked in his entry of 7 May 1752 that Mme 
de Pompadour and some ministers [perhaps D Argenson s brother, to whom 
the Encyclopedic had been dedicated] 17 have had D Alembert and Diderot 
entreated to devote themselves again to the work of the Encyclopedic, while 
practicing the requisite resistance to any temptation to touch upon religion 
or authority/ 18 This suggests that the anti-Jesuit coterie at the court, having 
somehow or other frustrated the Jesuits, were now in a position to turn to 
the former editors. Apparently those in responsibility had always intended 
to have the project eventually carried on somehow, probably because of the 
fact that many citizens and foreigners already had a vested interest in the 
Encyclopedic by virtue of having subscribed to it. 19 The jurisprudence of the 
ancien regime was especially regardful of property rights, and this deference 
to the vested rights of subscribers goes far to explain why the Encyclopedic 
was never permanently discontinued. 

As might be expected, considering the previous uproar, the agreement 
for recontinuing the Encyclopedic involved arrangements for new censors. 
This was the more necessary because the original censors appointed by 
D Aguesseau were patently finding very little to criticize. As we have al 
ready seen, the Abbe Tamponnet had given Volume I a clean bill of health 
in respect to theology and ecclesiastical history. Moreover, the censor Lassone 
had liked the second volume even better than the first: *As the materials 
are assembled, a great edifice is being formed, where one sees developing 
with equal methodicalness and utility the various treasures that the human 
race has acquired for itself by its researches. 20 This was not the way 
Mirepoix and the Jesuits spoke about the work! The solution to the prob 
lem was worked out by Malesherbes, who offered Mirepoix to have all 
articles without exception censored by theologians whom he would choose 

He accepted my proposition with joy, and nominated the Abbes Tampon- 


net, Millet, and Cottcrd, who were the ones in whom he had the most 

Volumes II [Malesherbes memory was at fault here; the new arrange 
ment was for volumes following the second], III, IV, V, VI, and VII of the 
Encyclopedic were censored in entirety by these three doctors. There was 
not a single article the manuscript of which was not initialed by one of 

the three. 21 

No direct evidence exists describing Diderot s attitude and policy during 
this crisis. One is therefore reduced to the indirect and speculative device 
of attempting to descry Diderot through the medium of D Alembert. For 
what D Alembert thought and said about it all was quite explicit. He 
took care to apprise Voltaire of his sentiments in a letter dated 24 August 
I752 ^ a i etter w hose main purposes were to bespeak Voltaire s protection of 
the Abbe de Prades and to thank him for the handsome remarks regarding 
the Encyclopedic that he had inserted in the closing lines of his great history 
of the age of Louis XIV (Le Sieclc de Louis XIV). My colleague in the 
Encyclopedic joins me in thanking you/ wrote D Alembert, and then, 
after alluding to the suspension of it, he continued, C I suspected that after 
having maltreated us as they did, they would come around to begging us 
to continue, and this has not failed to come about. For six months I refused, 
I shouted like Homer s Mars, and I may say that I gave in only because of 
the public eagerness/ D Alembert s giving in to the public eagerness sounds 
like a reluctant politician s being persuaded by his eager constituents to 
run. D Alembert used this letter to suggest, perhaps not very seriously, that 
it might be possible to edit the Encyclopedic in Berlin under the eyes and 
with the protection and enlightenment of your philosopher prince. 22 To 
this Voltaire, then resident at Potsdam, hastily replied that there is a pro 
digious number of bayonets here, but very few books. 23 But the principal 
interest in D Alembert s letter arises from his use of pronouns. By saying 
7 refused,* 7 shouted, 7 gave in, rather than using the collective we* which 
he employs elsewhere in these lines, he implies that Diderot s part was a 
subordinate one. This may be, for what evidence we have shows that D Alem 
bert made himself rather assertive that year. On i March he wrote to 
Formey at Berlin, Doubtless you have learned of the suppression of the 
Encyclopedic. I don t know whether the work will be continued, but I 
can assure you that it will not be by me. 24 In May, he was grumbling, in 
another letter to Formey, about the rather unfavorable review that the 
Preliminary Discourse had received at the hands of the Journal dcs Sfavans 
in its number of the previous September. He would not go on with the 


Encyclopedic, he wrote, unless the Journal des Sgavans makes me an authen 
ticated apology just as I shall dictate it. Moreover, he went on, there shall 
be given to us enlightened and reasonable censors, and not brute beasts in 
fur, sold out to our enemies. . . . There shall be allowed to us the sustaining 
of all opinions not contrary to religion or government, such as the one that 
all ideas come from the senses, which our illustrious Sorbonne would like 
to make a heresy of, and an infinity of others. ... It shall be forbidden to 
the Jesuits, our enemies, to write against this work, to say either good or 
ill of it, or else it shall be permissible for us to engage in reprisals. 25 But 
D Alembert was unable to secure any such stipulations. Perhaps because he 
could not obtain these guarantees, he informed some of his correspondents 
that he was henceforth limiting his role in the Encyclopedic. Thus he wrote 
to Formey on 10 July that in the future he would be responsible for the 
mathematical portion on condition that I shall not take part in the rest. 26 

D Alembert s assertions are a little self-contradictory and confusing, and 
they raise the problem as to the relative importance of the editorial roles 
of Diderot and himself. Was Diderot really the principal editor? Or was 
D Alembert in fact a co-editor with, in spite of the tide page - and for the 
mathematical portion, by M. d Alembert equal authority and respon 
sibilities? If not, D Alembert certainly seemed inclined to preen himself a 
bit before Voltaire as if he were. Voltaire, for his part, supposed for some 
years that D Alembert was in fact the work s principal editor, an impres 
sion which D Alembert does not seem to have disturbed when he visited 
Voltaire in 1756. It was not until Mme d Epinay visited Ferney in 1757 that 
Voltaire learned to his surprise how matters really stood. 27 At this moment 
in 1752 we see D Alembert (whose name, unlike Diderot s, had not ap 
peared on the publishers pay roll since early 1749) writing to Voltaire in 
such a fashion as to imply, by the use of pronouns, that the two men were 
co-editors, with Diderot the rather less active. Moreover, in refusing Frederick 
IPs proffer of the presidency of the Berlin Academy, D Alembert wrote in 
explanation on 16 September 1752: Besides I am in charge of a great work, 
as you know, conjointly with M. Diderot ... it is absolutely necessary that 
this work should be done and printed under our eyes, that we see each 
other often and work in concert upon it. 28 

The truth, however, about the relative responsibilities of D Alembert and 
Diderot in editing the Encyclopedic is symbolized throughout the several 
volumes of the work by the typographical devices used to identify the con 
tributions of each. D Alembert s identification was always the letter O, 
and thus he figured symbolically with all the other contributors, to each 



of whom a similar identifying letter had been assigned. Diderot s articles, 
on the other hand, were identified either by an asterisk or by no mark what 
ever In spite of this uniform and consistent symbolism, suggesting as it 
does that Diderot was always the principal editor, D Alembert s description 
of his functions was subject to somewhat confusing changes. He evidently 
thought of himself, in times of prosperity, as a co-editor; in times of ad 
versity, as a contributor. 

For some time the government contemplated the issuance of a new decree 
reauthorizing the Encydoptdie, but eventually decided against it and merely 
allowed the work to reappear on tacit sufferance and without public and 
explicit approval 29 The Government has appeared to desire that an enter 
prise of this nature should not be abandoned, 5 D Alembert was permitted 
to write in his preface to Volume III. Grimm, writing a confidential news 
letter, could be more circumstantial. The government, he wrote when 
Volume III was published, was obliged, not without more or less con 
fusion, to take steps to engage M. Diderot and M. d Alembert to undertake 
again a work that had been attempted in vain by some people who for a 
long while have occupied the least place in literature. I say with more or 
less confusion because the government entreated the authors to continue, 
but without revoking the decrees issued against the work three months 
before. 130 And in fact the Encydoptdie, though now allowed to proceed, 
henceforth did so on a very tentative and provisional basis in point of law. 
Painful though the episode had been, and abused as Diderot and D Alem 
bert considered themselves to be, their enterprise greatly profited in the 
long run from the temporary and evanescent triumph of the opposition. They 
survived, which is sometimes a very considerable feat in itself, as the Abbe 
Sieyes felt about his own part in the French Revolution. The enemies of 
Diderot and D Alembert had been unable to eliminate or supplant them 
or essentially alter the character of their encyclopedia. They had not been 
forced to disown either their principles or their methodology. Moreover, 
the turmoil had given their work an invaluable amount of publicity, as 
Barbier, who remarked upon it in his diary, had the shrewdness to see. 81 
Interest in the Encydopidic kept constantly mounting. The publishers had 
begun with plans for an edition of 1,625, which they presently increased to 
2000. When Volume III was published, in November 1753, interest had 
been so greatly stimulated that an edition of 3100 was necessary, with 
further reprintings planned to bring the first three volumes and all those 
thereafter to an edition of 4200. 32 The impact of the EncydopSdie, both 


numerically and in the nature of its ideas, was such that one of the great 
French critics, Ferdinand Brunetiere, said although he was consistently 
hostile to Diderot that it is the great affair of the time, the goal toward 
which everything preceding it was tending, the origin of everything that 
has followed it, and consequently the true center for any history of ideas in 
the eighteenth century/ 33 

A minor circumstance during 1752 gave Diderot his opportunity for 
scoring a considerable victory in polemics, and for stating with great vigor 
the methodological premises upon which the Encyclopedic stood. A well- 
known Jansenist prelate, the Bishop of Auxerre, decided to publish a 
pastoral instruction condemning the thesis of the Abbe de Prades. This was 
piling Ossa on Pelion, for it might be supposed that the Sorbonne, the 
Bishop of Montauban, the Archbishop of Paris, and the Pope, all of whom 
had pronounced on the matter, were competent to dispose of it. None of these 
was a Jansenist, however, and doubtless the Bishop of Auxerre felt that it 
was incumbent upon some Jansenist to prove his zeal for Catholicity at this 
juncture. But this intervention was skillfully exploited by Diderot, whose 
reply took the opportunity of playing off Jesuits against Jansenists, pro 
nouncing a plague on both their houses, and drawing a sharp contrast be 
tween matters of faith and matters of scientific fact. Diderot wrote this 
adroit exercise in polemics in the name of the Abbe de Prades, who was at 
that time in Berlin preparing his own apology, which was to appear in two 
parts. Accordingly Diderot entitled his little changeling, which was on 
sale in Paris even before the Abbe de Prades had published his, the Suite de 
I Apologie de M. I 1 Abbe de Prades . . . Troisieme partie ( Continuation 
of the Apology of the Abbe de Prades . . . Third Part ). The little book, 
which purported to be printed in Berlin, appeared about 12 October 1752, 
and was followed in 1753 by another edition, a pirated one published in 
Amsterdam. 34 

Problems of intellectual method were uppermost in Diderot s mind in 
writing this work, as is shown by the vigorous passage in which he defends 
reason against obscurantism: I know nothing so indecent and injurious 
to religion as these vague declamations against reason on the part of some 
theologians. One would say, to hear them, that men cannot enter into the 
bosom of Christianity except as a flock of beasts enters into a stable, and 
that one has to renounce common sense either to embrace our religion or to 
persist in it. To establish such principles, I repeat, is to reduce man to the 
level of the brute, and place falsehood and truth upon an equal footing. 3B 


In the preface Diderot said right out that this third part is as much the 
defense of the "Preliminary Discourse" of the Encyclopedic, from which I 
[he is writing in the name of De Prades] drew my first position, as it is 
the defense of my thesis. 36 And he lengthily discussed the implications in 
science and theology of the old axiom, by this time very familiar to the 
readers of this book, nihil est in intdlectu quod non prius juerit in sensu. 
Diderot once more expounded the sensistic psychology that Locke and 
Condillac had developed. But this antithesis of the notion that human beings 
are born with innate ideas of God and morality was particularly suspect 
among French churchmen, as we have seen, because these new ideas of 
psychology were likely to get confusingly mixed up with orthodox ideas 
about man s soul. The Bishop of Auxerre put his finger on the precise issue 
when he complained of De Prades s thesis that the type of man discussed 
therein Is not at all the man whose creation is described for us in Genesis. 38 
This was quite true. While the Bishop wanted to talk about Genesis, Diderot 
wanted to talk about man in nature, as he himself said, and then of the 
herd man (ks hommes en troupeau) and societal man (les hommes en 
sociftf)?* Thus we see Diderot trying to devise and apply concepts that 
are recognizable to us today as those fundamental to the social sciences. As 
a leading French social scientist has remarked, the principal effort of the 
Encyclopedists consisted in secularizing the social sciences. 40 That is ex 
actly what Diderot was trying to do here. But it was a point of view most 
upsetting to people who, when they said man, meant Adam. 

Diderot s life is an episode in the long history of the scientific attitude s 
struggle against the constrictions of authoritarianism. What he and people 
like him have always hoped and believed is that the methods of free inquiry 
can reveal more of ultimate reality than can an unbending orthodoxy. 
Diderot expressed this hope in the terminology of a liberal theologian when 
he has the pseudo-De Prades declare, I have believed that the wing of a 
butterfly, well described, would bring me closer to Divinity than a volume 
of metaphysics. 41 In this sentence is the difference between fundamentalism 
and science, between W. J. Bryan and Clarence Darrow. 

For persons of Diderot s cast of mind, the fate of Galileo was always the 
hobgoblin that haunted their imaginations and inhabited their fears. And 
consequently Diderot has De Prades distinguish between what was appro 
priate to theology and what to philosophy : Let us take care not to identify 
the truth of our religion and the divinity of our Scriptures with facts that 
have no relation to these subjects and which might be overturned by time 
and by experiments. . . . We damage both theology and philosophy if we 


take it into our heads to produce physicists in our [theological] schools 
and if philosophers begin to make theologians in their assemblies. 42 

Thus Diderot took the opportunity inadvertently offered him by the 
maladroit Bishop of Auxerre to strike a blow for what the eighteenth century 
proudly and perhaps a little vaingloriously called enlightenment. In doing 
so, Diderot belabored the Bishop a little, as when he wrote that it seems 
to me that this prelate has pronounced very superficially about topics that, 
to tell the truth, he was not required to understand, but upon which he 
was much less required to speak, and infinitely less required to insult those 
who do understand them/ 43 This was a way of showing, as indeed was 
the purpose of the whole book, the pains and penalties awaiting those who 
attempted to overawe the partisans of the new learning. But this was, after 
all, a negative and defensive tactic. More important was the appeal to tolera 
tion, and the assertion that De Prades and people like him were being unjustly 
persecuted. Such was the burden of Diderot s peroration, which Buffon 
himself a famous connoisseur of literary style considered to be one of 
the most eloquent passages in the French language. 44 Similarly extravagant 
in its praise was the judgment of a journalist of the time who wrote that 
some of the passages in the Apology, especially the one at the end, would 
make one suppose that they had been written by a resuscitated Bossuet, 
a remark which, for a generation dazzled by the literary glories of the 
century of Louis XIV, was the highest possible praise. 45 

Doubtless as he wrote the conclusion, Diderot was seeing himself in the 
figure he drew of the persecuted Abbe de Prades. There is a vein of the 
atricality in the philosophes (and in Diderot) which makes it a little dif 
ficult to take them quite so seriously as they took themselves. And a good 
deal of this sense of the dramatic and even of the self-righteous appears in 
Diderot s closing remarks. But there is persuasiveness and conviction in 
them, too, from an author who had had his share of perturbations and alarms: 

... I have seen that the state of all these people [his critics] is beyond hope, and I 
have said, Therefore shall I forget them; such is the counsel both of my religion 
and of my self-interest. I shall devote myself without respite to the great work that 
I have undertaken; and I shall finish it, if the goodness of God allows me to 
do so, in a manner that some day will make all my persecutors ashamed. At the 
head of such a work my vindication will find its appropriate place; it is at the begin 
ning of a treatise on the truthfulness of religion that it will be fitting to place the 
story of the crying injustices that I have suffered, of the atrocious calumnies with 
which I have been blackened, of the odious names lavished against me, of the 
impious conspiracies by which I have been defamed, of all the evils of which I 


have been accused, and of all those that have been done against me. There, then, 
will this story be found; and my enemies will be confounded; and the people of 
virtue will bless the Providence that took me by the hand, when my uncertain 
steps were faltering, and that brought me to this land where persecution shall 
not follow me. 46 

Thus he concluded, in a pleasant incandescence of self-approval. 


Italian Opera and French Taste 

D 1 

DIDEROT was an extremely sociable man. He liked 
to oblige people. And he loved to talk. He spent 
so much time pouring forth his ideas to friends and acquaintances that 
it is remarkable that he ever found the opportunity to accumulate new 
stock. With Diderot communication was almost a compulsion. If absent 
from his mistress, he wrote her long letters; if left to his own devices, his 
works show that his thought patterns were set in a subtle dialectic of com 
munication with himself; and if with friends, even casual acquaintances, 
he lavished his ideas upon them in such profusion that Grimm, tidy German 
and shrewd entrepreneur that he was, would frequently deplore the non 
chalant outpouring of such dazzling gifts, much as a man who is part 
owner of an oil well might deplore the wastefulness of a gusher that has 
blown its top. 

Moreover, Diderot delighted in thinking of himself as the very type and 
pattern of the Good-natured Man. 1 Consequently, he did not mind ex 
pending his time and his energies in behalf of those who had no real claim 
upon him. Nor did he really object to being imposed on, up to a certain 
point, for it fitted into his picture of himself as an affable, approachable, 
and generous person. This is illustrated by an anecdote that he told of 
himself as occurring at about this time in his life. Once upon a time I 
rescued from extreme poverty a young man of letters who was not without 
talent. I fed him, lodged him, kept him warm and in clothes, for several 
years. The very first flight of this talent which I had cultivated was a satire 
against me and mine. The publisher . . . suggested suppressing the work. I 
took care not to accept this ofler. The satire appeared. The author had the 
impudence to bring me the first copy of it himself. I contented myself with 
saying to him: "You are an ingrate. Anyone else than I would have thrown 
you out, but I am obliged to you for knowing me better than that. Take 



back your work and carry it to my enemies, to that old Due d Qrleans who 
lives on the other side of the street." I was living at that time in the 
Estrapade. The end of all this was that I wrote for him, I against my own 
self, a petition to the Due d Orleans, that the old fanatic gave him fifty 
louis, that the thing became known, and that the protector remained pretty 
ridiculous and the protected pretty vile/* 2 

Diderot s extraversion did indeed carry with it the constant risk that he 
would dissipate his energies and allow himself to be distracted from more 
substantial accomplishment. It may be doubted, however, whether the 
profusion of Diderot s personality and ideas was really as wasted as Grimm 
feared. Among all of the philosophcs Diderot was chief. In the vocabulary 
of his friends, he was more than a philosophy, he was THE philosophe. He 
was the leader of a party or, as his enemies would put it, of a sect. And it 
was by conversation as much as it was by what he published that he spread 
his influence and made his leadership felt. Perhaps even more; for much 
of what he thought was too dangerous to publish and had to remain in his 
desk drawer to await the random honors of posthumous publication. But 
his ideas, orally expressed, emanated in pulsations from the social circles 
that he frequented out into that highly centralized society in which every 
thing focused upon Versailles and Paris, Add to this that Diderot was ex 
traordinarily gifted in the arts of oral persuasion (many of his friends 
thought that, given different political conditions in France, he would have 
been an orator of the very highest rank), and it can readily be seen that not 
all the time he spent in company was wasted. 

The ideal milieu in which to gratify his social proclivities was provided 
Diderot by the Baron d Holbach, a man with whom Diderot became intimate 
about this time and who, like Grimm, was destined to remain a lifelong 
friend, D Holbach s house, with its fine library and its quite extraordinary 
collections of prints and natural history, and D Holbach s dinners attracted 
some of the greatest wits and intellects of his century. David Hume took 
Horace Walpole there in 1765, and the latter, recording the visit in his 
journal, spoke of D Holbach as *a good-natured German settled in France, 
who keeps a table for strangers, the beaux esprits of the country etc. 3 
Horace Walpole s judgment of persons was apt to be a little reductive, so 
that Morellet s testimony is valuable in revealing what the opportunities 
at D Holbach s meant to persons of the philosophical persuasion: 

* The time, the street Diderot was living in, and the fact that he spoke of the publication as 
being against me and mine" suggest that this may have been La Bigarure s account of the brawl 
between Mme Diderot and Mmc dc Puisieux. 


Baron d Holbach served two dinners regularly each week, Sundays and Thurs 
days; there assembled then . . . ten, twelve and up to fifteen or twenty men of 
letters and men of the world or foreigners ... a society truly engaging, as could 
be realized by this symptom alone, that, being arrived at two o clock, as was the 
fashion at that time, we often were almost all of us still there at seven or eight 
in the evening. 

Now, there was the place to hear the freest, most animated and most instructive 
conversation that ever was. . . . There was no moot point, political or religious, 
that was not advanced there and discussed pro and con, almost always with great 
subtlety and profundity. 

It is there that I heard . . . Diderot treat questions of philosophy, art, or litera 
ture, and by his wealth of expression, fluency, and inspired appearance, hold our 
attention for a long stretch of time. 4 

Paul Thiry, Baron d Holbach, later became the secret author of a long 
series of works which have qualified him in the eyes of posterity to be 
considered one of the paladins of atheism. Born in 1723, he was just ten 
years younger than Diderot. He was reared at Paris and educated at the 
University of Leyden, where he made friends with John Wilkes, the tempes 
tuous Englishman who in the 1760*5 became the hero of the resistance to 
general warrants (a sort of British counterpart of the French lettres de 
cachet) and who, in other ways as well, fell foul, like the Americans, of 
George Ill s attempts at personal rule. It was through D Holbach that 
Diderot twenty years later made the acquaintance of Wilkes, who had 
become by then one of the best-known, not to say most notorious, men in 
Europe. 5 

D Holbach settled down in Paris following the War of the Austrian Suc 
cession, became naturalized in 1749, and married, in decorous succession, 
two sisters, his second cousins. 6 These matches gave every indication of 
being for love, but they also served to keep the considerable family fortune 
under one roof, so that D Holbach never had to worry, nor did any of his 
philosophical friends, where the next meal was coming from. That roof, 
still standing at Number 8, Rue des Moulins, covers a substantial five-storey 
building (six, counting the entresol) with its own court and porte-cochere. 7 
In Diderot s day it was located in an area of tortuous and tangled streets 
which has since been much simplified by building the Avenue de 1 Opera. 
Another acquaintance of Diderot, Helvetius, lived hard by. It is difficult 
to say when Diderot first knew D Holbach but it must have been at least 


some months before 1752, to judge from the latter s numerous contributions 
to Volume II of the Encyclopedic. 8 There is direct evidence of their con 
nection by October of that year, for a French writer returning from Berlin 
mentioned meeting Diderot at the home of Mme d Aine, D Holbach s 
mother-in-law. 9 

Diderot and D Holbach had a great deal in common, not only intellectually 
but also in matters of preference and taste. For instance, they both liked 
to overeat, they liked a walk in the country, they liked to possess fine prints 
and beautiful paintings, and they liked comfort. Also, without being pro 
miscuous, they were both heartily heterosexual. In matters of philosophy 
and religion, they were in substantial agreement, although Diderot s doctrine 
is much more elusive, ambiguous, and therefore closer to life than D Hol 
bach s. Diderot s philosophy, hard to be sure of, has a great deal of poetic 
insight, and should properly be called godless rather than atheistic (to use 
a distinction frequently employed to discuss one aspect of the existentialism 
of Sartre). But there never was any question that the D Holbach whom 
posterity knows was solidly and ponderously atheistic. 

Oddly enough, there is testimony, although not of impeccable quality, 
that Diderot converted D Holbach to atheism. The evidence comes from a 
book by a politician and man of letters named Garat, who in his younger 
days knew both men and was especially friendly with a member of their 
circle named Suard. Suard knew Diderot and D Holbach at this early 
time and is the source of the following story: Having long been an adorer 
of God, Whom he [D Holbach] saw in the order and laws of the universe, 
he had a missionary s zeal in regard to those whom he liked and who did 
not have the same belief. He pursued the incredulity of Diderot even into 
those workshops where the editor of the encyclopedia, surrounded by ma 
chines and workers, was taking sketches of all the manual arts; and draw 
ing his text from these very machines ... he asked him if he could doubt 
that they had been conceived and built by an intelligence. The application 
was a striking one, but it did not, however, strike either the mind or heart 
of Diderot. Diderot s friend, bursting into tears, fell at his feet. It has been 
said of Saint Paul, thrown from the horse upon which he was pursuing the 
Christians: Falls a persecutor, and gets up an apostle. It was quite the con 
trary that occurred in this instance: he who fell on his knees a deist, got 
up an atheist. 10 There may indeed be something to this story, for as late 
as 1756 the cure of Saint-Germain-PAuxerrois in Paris enthusiastically 
vouched for D Holbach as making profession of the Catholic, apostolic 
and Roman faith, the duties of which he fulfills with edification. n 


However this may be, it is incontestable that Diderot and D Holbach had 
innumerable intellectual interests in common, interests which might quite 
literally be called encyclopedic. Marmontel wrote of D Holbach that he 
had read everything and never forgotten anything of interest/ and Rous 
seau spoke of him as maintaining his position among men of letters very 
adequately, owing to his knowledge and learning. 12 This passion for knowl 
edge, especially in the fields of mineralogy and metallurgy where a mastery 
of German was essential, was extremely useful to the Encyclopedic and 
was acknowledged lengthily in the foreword to Volume II. 

The consonant tastes of Diderot and D Holbach were particularly re 
vealed in this period 1752-4 by their taking the same side in an embittered 
debate over the comparative merits of the French and the Italian opera. On 
i August 1752, a visiting Italian company came to the French Opera, then 
holding forth where the Palais Royal is today, and made their debut by 
singing Pergolesi s opera bouffe, La Serva padrona. This company continued 
to give their repertory at the Opera, singing once, twice, or sometimes three 
times a week until their final performance on 7 March I754- 13 All of their 
thirteen pieces were short and consequently given either as curtain raisers or 
as concluding pieces with another work. The other attraction was always 
a piece from the regular French repertory, given by the regular company, 
so Parisian audiences had an excellent opportunity to make comparisons. 

During a year that had already been enlivened by the Abbe de Prades 
affair and the suspension of the Encyclopedic, and that also saw tension 
heightening between the King and the Parlement of Paris caused by a very 
grave quarrel as to whether dying Jansenists could be denied the last rites 
if they refused to subscribe to the bull Unigenitu$ & disagreement which 
ended with the exiling of the Parlement to a provincial town in 1753 and 
the temporary suspension of their functions in addition to all this, there 
began the quarrel of the buffoons, in which the Encyclopedists found com 
mon and exciting cause. The enthusiasts for the new Italian genre tended 
to congregate in that part of the pit at the Opera that was near the royal 
box assigned to the Queen. Consequently Queen s Corner 5 came to be the 
name for the aficionados of the Italian opera, while King s Corner de 
nominated the partisans of the French. 

In D Holbach s circle Jean-Jacques Rousseau had extolled the beauties 
of the Italian opera, of which he had had firsthand experience at Venice. 
Rousseau s friends could now judge for themselves, and what they heard 
charmed them utterly and seemed infinitely superior to the formalism and 
intellectualism of the conventional French opera which Lully (1632-87) 


had created. They found the Italian opera richer and more varied in musical 
devices, more melodious, more capable o building emotional mood, more 
adroit in suiting the music to the phonetics and meaning o the words. In 
contrast, French operatic music seemed stiff and monotonous, with long, 
boresome recitatives, and too much emphasis on harmony at the expense of 
melody. This last, they thought, was an inherent difficulty of the French 
language, which caused singers to bawl rather than sing. Although the 
French opera was excellent as a spectacle, it left much to be desired from 
the point of view of music. As the great Italian playwright Goldoni said of 
it, it was heaven for the eyes, hell for the ears. 14 The French partisans of 
such pieces as La Serva fadrona and Pergolesi s other comic opera heard in 
Paris at that time, // Maestro di musica, were quite in agreement with this 
sentiment, and Rousseau wound up his Lettre sur la musique jrangaise by 
declaring, after a good deal of hyperbole, that the French have no music 
and cannot have any, or ... if ever they do have any, it will be so much 
the worse for them.* 15 

During the quarrel of the buffoons, tempers reached an unbelievable 
pitch. Rousseau and Grimm, for example, were convinced that the former 
narrowly escaped arrest by lettre de cachet because of his Lettre sur la 
musique jranqaise Practically all of the Encyclopedists participated in 
the pamphlet war especially Rousseau, Grimm, D Holbach, and Diderot 
and, characteristically enough, they all espoused the Italian side. They 
were never afraid of novelty, although their attitude was regarded by many 
of their enemies as practically a national betrayal. On the whole, wit was 
on their side, apoplexy on that of their opponents. The most effective 
pamphlet, and one still very amusing to read, was written by Grimm. This 
was Le Petit Profhete de Boehmischbroda, done in Scriptural language in 
an earnest, solemn, and deliciously naive style. Even the outlandish place 
name of Boehmischbroda was funny. The Little Prophet, a famished mu 
sician in a Prague garret, was magically transported to the Paris Opera, and 
what he saw and heard there, although he accepted it at its face value, 
would not, in the language of eighteenth-century English pamphleteering, 
bear examination. 17 This pamphlet deservedly established Grimm s reputa 
tion as a wit, and in the years to follow, Diderot s favorite and familiar 
epithet for him was prophet. Diderot himself, whom Romain Rolland 
credited with a very exact knowledge of music, also entered the lists. 18 In 
his Memoirs on Different Subjects of Mathematics he had already proved 
his competence in musical theory from the point of view of mathematics 
and physics, and it will be remembered that he probably assisted Rameau 
in preparing some of his works for publication. Now, in early 1753, Diderot 


contributed three anonymous pamphlets to the controversy. They were en- 
tided Arret rendu a I amphitheatre de V Opera ( Judgment Rendered at the 
Opera Amphitheatre ), Au Petit Prophete de Boehmischbroda ( To the 
Little Prophet of Boehmischbroda ), and Les Trois Chapitres, ou La Vision 
de la nuit du mardi-gras au mercredi des cendres ( The Three Chapters, 
or, The Vision of the Night from Shrove Tuesday to Ash Wednesday ). 19 
These pamphlets, though entertaining enough, are topical and ephemeral, 
and need not greatly detain a twentieth-century reader. What is perhaps most 
noteworthy about them is their air of moderation and conciliation. If, from 
the center of the pit, whence I raise my voice, I were fortunate enough to 
be heard by both the "Corners" . . . , he wrote a statement which gives 
the impression that perhaps he was seeking to avoid making irreconcilable 
enemies of Rameau, who was after all a great contemporary composer, and 
his partisans. 20 

Of course Diderot in reality favored the Queen s Corner. Already in 
UOiseau blanc (1748) he had spoken briefly, but in praise, of Italian music. 21 
At about this time Grimm reports it in August 1753 Diderot amused 
himself by composing a Latin motto to be painted (naturally it was not) on 
the curtain of the Opera. The inscription clearly shows what he thought 
of the French opera of his day, but it is so laconic and lapidary that an ex 
planation dilutes its humor: Hie Marsyas Apollinem?* This refers to the 
myth that Apollo, the god of song, flayed alive a very presumptuous and 
un-immortal mortal named Marsyas for presuming to challenge him to a 
singing contest. The piquancy of Diderot s motto is that it has no verb and 
therefore the nominative and accusative cases of the proper names carry 
all the meaning, which runs something like this: Here Marsyas [takes 
the hide off] Apollo/ 

From the point of view of the Encyclopedic, the quarrel of the buffoons, 
although it served to unite the brethren in a common cause, presented an 
awkward contingency: it could cause trouble with Rameau. D Alembert, 
as well as Diderot, had been on very friendly terms with him in earlier 
years. Moreover, Rameau had been asked to do the articles on music for 
the Encyclopedic but had refused, although he offered to look over and 
criticize the articles when prepared by someone else. 23 In consequence, the 
assignment was given to Rousseau, whose pieces, according to a modern 
critic, offered a faithful if somewhat jumbled and at times inept picture 
of Rameau s discoveries. 24 Rousseau himself acknowledged his poor work 
manship, saying that Diderot had wanted him to get them done in three 
months, and that he did so, but very hastily and very badly. 25 Paren 
thetically, we may very well wonder why Editor Diderot did not see to 



it that the articles were improved, either by insisting that Rousseau revise 
them or by submitting them to Rameau for criticism. Perhaps he did not 
because Rousseau was so touchy as to render either alternative impractical, 
a hypothesis suggested by Rameau s remark that your Foreword makes 
sufficiently evident the reason that prevented you: it is better not to give 
offense to one s colleagues than to the public. 26 Perhaps, too, Diderot and 
D Alembert, not subscribing to all of Rameau s ideas, did not want to 
make the Encyclopedic a vehicle for them. 27 

At all events, the stand taken by the Encyclopedists in the quarrel of the 
buffoons made the Encyclopedic vulnerable, for their decided preference 
for Italian music might irritate Rameau into publicly remarking about some 
of the insufficiencies of the Encyclopedic articles on music. Evidently it was 
not the intention of the Encyclopedists to stir him up. Most of them spe 
cifically excepted him from their strictures regarding Lully and the school 
of French opera in general, and Diderot praised Rameau in the Arret rendu 
h I amphithtdtre de I Optra?* He was taken as the exception proving the 
rule. But how could the tradition of French operatic music be attacked with 
out including in the censure the greatest living practitioner of it? So, at 
least, Rameau appears to have thought, and in a series of little books he 
presently began to show the deficiencies of Rousseau s unfortunate articles. 
In 1755 he published Erreurs sur la musique dans VEncy dope die, in 1756 
Suite des erreurs sur la musique dans l f Encyclopedic, and in 1757 Reponse 
de M. Rameau a MM. les editeurs de I Ency clop t die. This sort of controversy 
did not help the Encyclopedic. It was probably no exaggeration when a 
journal hostile to the Encyclopedic remarked that Rameau s brochures made 
a great sensation among the public. 29 Diderot s irritation is attested by his 
unflattering description of Rameau in Rameau s Nephew, a dialogue that 
was not intended for publication in Diderot s lifetime but that still served 
(perhaps all the more) as an outlet for emotional release. 

Rousseau, not content to lecture the French public by precept, under 
took at this time to teach it by example. The result was his extremely suc 
cessful operetta, Le Devin du Village ( The Village Soothsayer ), for which 
he wrote both words and music. In October 1752 the operetta was given 
before the King at Fontainebleau, a circumstance which indirectly led to 
the first open disagreement between Diderot and Rousseau. Jean-Jacques 
had been invited to meet the King the day following the showing, an inter 
view that would have been almost certainly followed by the granting of a 
much needed pension. But for a number of reasons Rousseau returned to 
Paris instead, a decision which Diderot disapproved of so heartily that he 


sought out Rousseau to tell him so. Although I was moved by his zeal/ 
wrote Rousseau, I could not subscribe to his maxims, and we had a very 
spirited dispute, the first that I had ever had with him; and we never have 
had any other save of this kind, he prescribing to me what he contended 
I ought to do, and I resisting because I believed I ought not to do it. 5 30 

It is possible that Diderot came to feel subconsciously that in the quarrel 
of the buffoons Rousseau had carried them too far. This is, however, com 
pletely conjectural. It is true, though, that tensions were already beginning 
to develop between Rousseau and the other Encyclopedists. He was inclined 
to think that it was because they were jealous of the success of Le Devin 
du Village, but Rousseau was a suspicious and highly imaginative man, 
and it is by no means certain that his fellow Encyclopedists were jealous of 
him. As Mme de Stael, writing about Rousseau ten years after his death, 
said of him, Sometimes he would leave you still loving you; but if you 
had said a single word that could displease him, he recalled it, examined it, 
exaggerated it, thought about it for a week, and ended up by quarreling 
with you. . . . 31 But even if the other Encyclopedists were jealous of him, 
the emotional and intellectual causes of the eventual disruption were much 
subtler and deeper. It is quite surprising that the philosophes had not al 
ready realized how litde of a philosofhe Rousseau was. He did not have 
the faith that they did in the march of knowledge, in progress, and in reason. 
For years, apparendy, they regarded his diatribe against the arts and sci 
ences as more of a paradox than a conviction, failing to understand how 
deeply committed he was to this outlook on life. Rousseau believed in 
progress, too, but it was a progress that consisted in getting back to the 
uncomplicated and the undifferentiated, to the spirit of the simplicity and 
primitivism of a state of nature. This was not the point of view of men who 
believed in progress, as the Encyclopedists did, in terms of ever increasing 
knowledge, ever increasing technology, ever increasing understanding and 
domination of nature. 

In fact, the signs of eventual disagreement could plainly be read in the 
disobliging way in which Rousseau spoke of philosophy* in the preface that 
he wrote to his unsuccessful comedy, Narcisse. This preface was written in 
December 1752 and published sometime in the first half of the following 
year, and could hardly please people who prided themselves on being called 
philosophers, for it discredited the very name. The taste for philosophy/ 
wrote Rousseau, relaxes all the bonds of esteem and benevolence that attach 
men to society. . . . Soon the philosopher concentrates in his person all the 
interest that virtuous men share with their fellow men: his disdain for others 



turns to the profit of his own pride; his self-love increases in the same ratio 
as his indifference for the rest of the universe. Family, fatherland, become 
for him words empty of meaning; he is neither a parent, nor a citizen, nor 
a man; he is a philosopher. ** These are strong and, indeed, quarrelsome 
words. Yet the philosophy were content to ignore them. 

An incident on Shrove Sunday, 3 February i 75 4> in which both Diderot 
and Rousseau figured, gives some measure of Rousseau s growing irritation 
and malaise in his Encyclopedist associations. Superficially, the incident 
would seem to be no more than a disagreement over whether or not a certain 
situation was funny. But frequently like and unlike can be measured by what 
seems amusing to the one and deplorable to the other. What happened was 
this. In the summer of 1753 while walking in the Luxembourg Gardens, 
Diderot was introduced to a young cure* from a small parish in Normandy, 
the Abbe Petit. He expressed delight at meeting the philosophe, for the 
Abbe wanted Diderot s comments on an original madrigal, seven hundred 
verses long. Diderot paled and told the Abbe" that he ought to write tragedies 
and not waste his time on madrigals. Termit me, then, to say to you that I 
won t listen to a single verse of yours before you bring us a tragedy. Some 
months later the Abbe showed up with his tragedy, and Diderot arranged 
for him to read it at D Holbach s. 33 The tragedy, D Holbach later recalled, 
was preceded by a discourse on theatrical composition so absurd that his 
listeners could not take him seriously. 1 will confess that, half-laughingly, 
half-soberly, I myself strung the poor cure along. Jean-Jacques hadn t said 
a word, hadn t smiled an instant, hadn t moved from his armchair. Sud 
denly he rose up like a madman and, springing towards the cure, took his 
manuscript, threw it on the floor, and cried to the appalled author, "Your 
play is worthless, your dissertation an absurdity, all these gentlemen are 
making fun of you. Leave here, and go back to do curate s duty in your 
village. . . ." Then the cure got up, no less furious, spewed forth all 
imaginable insults against his too sincere adviser, and from insults would 
have passed to blows and to tragic murder if we had not separated them. 
Rousseau left in a rage, which I believed to be temporary, but which has 
never ceased and which has done nothing but increase since that time.* 34 

This lively picture of Diderot and Rousseau in the company of their 
peers is complemented by another recollection of about this time, this one 
by the Abbe Morellet. It shows Diderot in his dressing gown in the privacy 
of his own home talking to men much his junior. The Abbe Morellet was 
twenty-five years old at the time and a theological student. His recollections 
of Diderot agree with those of almost everyone else who knew him well 


easy of access, generous of his time, full of ideas, and vivacious in the expres 
sion of them, sociable perhaps to a fault, and eager to persuade others to his 
line of thought: 

The conversation of Diderot, an extraordinary man whose talent can no more 
be in dispute than his faults, had great ability and great charm. His discourse was 
animated, carried on in perfect good faith, subtle without being obscure, varied 
in form, brilliantly imaginative, fecund in ideas, and awakening ideas in others. 
One allowed oneself to be carried away by it for hours on end, as upon a gentle 
and limpid stream flowing through a rich countryside ornamented with fine habita 

I have experienced few pleasures of the mind to surpass it, and I shall always 
remember it. 

. . . there never was a man more easy to live with, more indulgent than Diderot. 
He lent, and even gave, wit to others. He had in mind the desire to gain proselytes, 
not precisely to atheism, but to philosophy and reason. It is true that if religion 
and God Himself chanced to be in his path, he would not have known how to stop 
or turn aside; but I have never observed that he put any heat into instilling opin 
ions of this sort. He defended them without any acrimony, and without looking 
unfavorably upon those who did not share them. 

. . . The recollection of my Sunday meetings with Diderot leads me to speak 
of an abbe whom I sometimes met at his house, the Abbe d Argenteuil. . . . He 
took it into his head to convert Diderot, and, inspired by a fine zeal, came to 
preach to him at the Estrapade. . . . 

I shall always remember our mutual embarrassment the first time we encoun 
tered each other, and the excellent scene we provided Diderot, who saw us in his 
study as two shamefaced libertines meeting face to face in a house of ill repute. 
But after the first peals of laughter, we began to dispute. And there were the 
Abbe d Argenteuil and I, carried on by the march of the conversation and enter 
ing into questions regarding toleration, while the philosopher, seeing the wran 
gling begun, put his hands into the sleeves of his dressing gown and made him 
self judge of the thrusts. 35 

Other glimpses into Diderot s private life at this time are afforded us. For 
one thing, we know that the family income had become greater. Beginning 
with 1751 the publishers paid Diderot five hundred livres quarterly. This 
was still far from being princely. There can be no doubt that the publishers 
purchased the services of a man of Diderot s ability at a very modest rate, 
and that they really did exploit him. Still, money was easier than it had 
previously been in the Diderot household, and this rate of payment con 
tinued until the beginning of I755- 36 Of more than a little interest is the fact 


that in 1752 Mme Diderot visited her relatives-in-law at Langres for die 
first time. To judge as best we can from a letter to Mme Caroillon La 
Salette, now almost illegible, Diderot had hopes that she could do something 
to soften the intractability of Mme Diderot s character. 37 At all events, the 
visit terminated in mutual liking and esteem. And in the early weeks of 
I7 Diderot, with his usual eagerness to do a friend a favor, moved heaven 
and earth in behalf of a fellow-townsman of Langres. Nicolas Caroillon, 
son-in-law of Pierre La Salette, wanted to be designated as the successor 
of his father-in-law in the lucrative post of bonded tobacco warehouseman 
in Langres. The episode has more than one facet of biographical interest. 
In the first place, some faint stirrings of an old sentimental attachment may 
have inspired Diderot, for Caroillon s wife, nte La Salette, may have been 
one of his first calf-loves. 38 Secondly, by Ms assistance in this instance, Diderot 
put into his debt a family that eventually was to be linked to his by marriage. 
Thirdly, and most of all, the incident shows his eagerness to be obliging. 
As his daughter wrote of him, three-fourths of his life was spent in aiding 
all those who had need of his purse, his talents, or his negotiations. 39 And 
with this desire to be helpful was compounded a certain gratification at 
being able to show off Ms prominent and influential connections. 

Getting the position for Caroillon was an animated and complicated in 
trigue, involving some methods that one would like to think disappeared 
with the ancien regime. The mistress of the Controller General was promised 
two hundred louis, but it took another fifty before the matter was pressed 
to a successful conclusion; the private secretaries of the Controller General 
were friendly to Diderot and willing to attempt to secure for him an ap 
pointment with the minister; Buffon, who is very fond of me, wrote a 
supporting letter; and the Controller General himself, Machault d Arnouville, 
unexpectedly consented to see him. I believe, 1 wrote Diderot complacently, 
I owed this favor somewhat to his curiosity to see a man who had made 

such a stir. * 

Having thus tried to accomplish his purpose through the Controller Gen 
eral, Diderot also undertook to secure the support of the King s mistress. 
This he attempted to do through a personal friend, one of the celebrated 
names of the eighteenth century, a man who was Mme de Pompadour s 
official physician. This was Francois Quesnay (1694-1774), the founder of 
the physiocratic school of economic theory. Diderot was greatly influenced 
during the 1750*5 and the early 1760 $ by Quesnay s views, and opened the 
columns of die Encyclopedic to Quesnay s lengthy and substantial articles 
on Farmers (Fermiers) and Grain. 41 These articles afforded an excellent 


means for the diffusion of physiocratic ideas. Quesnay was very critical of 
the existing French national economy and the laws regulating it, for he 
felt that they put a premium on the production of luxury goods and the 
growth of cities at the price of impoverishing and depopulating the country 
side. 42 It is easy to see how much influence Quesnay s thought exerted upon 
Adam Smith, for both men were seeking to understand the causes of the 
wealth of nations, and both the older man more by implication preached 
the virtues of increasing the net national product by allowing matters to 
proceed not by mercantilistic regulation but by the grace of the invisible 
hand. It is therefore true to say, as has often been done, that Diderot s 
friend Quesnay was one of the fathers of the science of political economy. 

Quesnay, according to Marmontel, was lodged in very cramped quarters 
in the entresol above Mme de Pompadour, [and] occupied himself from 
morning to night with nothing but rural economy/ In a passage that is 
intensely interesting but unfortunately uncorroborated by any other memoir 
writer of the day, Marmontel went on: Below us they were deliberating 
concerning war and peace, the choice of generals, the dismissal of ministers, 
while we, in the entresol, argued about agriculture, calculated the net 
product, or sometimes dined gaily with Diderot, D Alembert, Duclos, 
Helvetius, Turgot, Buffon; and Mme de Pompadour, not being able to 
induce this troop of philosophers to come down to her salon, came up herself 
to see them at table and chat with them. 43 

For the purpose of getting the Langres appointment for his friend Caroil- 
lon, Diderot presented a memorandum to Mme de Pompadour through the 
good offices of Quesnay, received word from her through the same channel, 
and then wrote to her directly. The upshot of it all was that Caroillon got 
his appointment and Diderot, who evidently was not quite as convinced 
of Caroillon s transcendent qualifications for the post as he said he was, 
wrote him a page of good advice upon the scrupulous fulfillment of his 
official duties. 44 

It is interesting, incidentally, that Diderot kept his wife informed of the 
vicissitudes of this solicitation, showing that he did not always exclude her 
from his affairs. 45 Meanwhile, Mme Diderot had news of her own during 
this year, for Diderot remarked to the Caroillons in February that his wife 
had been very ill with morning sickness. 46 Childless Mme Diderot was 
forty-three years old at the time of this latest pregnancy, for which she had 
prayed many years. My mother took a vow to dress in white the next child 
to be born to her and consecrate it to the Holy Virgin and Saint Francis 
[a custom which, though it has become comparatively uncommon in France, 


is not unheard of to this day]. Nothing could get it out o her head that I 
owe my existence to this vow/ 47 Marie-Angelique Diderot, Angelique after 
her paternal grandmother, was born in the house on the Rue de 1 Estrapade 
on 2 September 1753, and baptized at the parish church of SaintJBtienne- 
du-Mont the next day. The child s godparents, persons not otherwise known 
to posterity, declared themselves unable to sign their own names. 48 Now, 
for the fourth time, there was a baby in the house. This one was destined to 
a long life. 


Diderot s Thoughts on the Interpretation of Nature 

NE OF the ways in which the philosophe Diderot 
proved himself a philosopher was in his con 
tributions to the philosophy of science. Evidence of this is especially to be 
found in a booklet written while he was engaged in the preparation of Vol 
ume III of the Encyclopedic. This essay one of his most important and 
least read was the Pensees sur I interpretation de la nature ( Thoughts on 
the Interpretation of Nature ). An extremely rare edition of the Pensees, al 
most a pilot copy, was printed in I753- 1 The two editions published in 1754 
are more ample and better known. The work, though anonymous, was au 
thorized. D Hemery noted in his journal that the Pensees, attributed to 
Diderot, had been published with tacit permission, another interesting and 
representative example of Malesherbes policy of keeping the press as free as 
he could. 2 

The Pensees sur I interpretation de la nature is a short book devoted to 
taking stock of some of the current implications of the scientific method 
and was intended to be a handbook for the philosophy, the new learning, 
of the day. The somewhat solemn exordium addressed To Young People 
Preparing Themselves for the Study of Natural Philosophy/ which set 
Diderot s enemies laughing scornfully, reflects the seriousness of the author s 
purpose/Tfoung man, take and read, it began. The pages that followed 
opened up new points of view, sometimes by positive statements, sometimes 
by asking questions, sometimes by stating what Diderot labeled conjectures. 
It was a book that suggested many of the most important problems in the 
philosophy of science, a tentative book sending out patrols along the frontiers 
of knowledge. And to at least one modern critic, comparing it with Descartes, 
Diderot s little book seems to be the Discourse on Method of the eighteenth 

century. 3 

It might, however, be more accurate to say that the book was the Novum 



Organum of the eighteenth century. For the Thoughts on the Interpretation 
of Nature was more Baconian than any other of Diderot s writings. Both in 
structure and in approach Diderot modeled his book on Bacon, whom he 
had been carefully studying for ten years according to the testimony of one 
of his friends. 4 For instance, the tides of the two books were significantly 
similar; the Novum Organum is subtitled True Directions concerning the 
Interpretation of Nature. 5 Moreover, the arrangement of the two books 
in a series of disjunctive paragraphs or aphorisms, as Bacon called them, 
is exactly alike. And Diderot possibly was influenced by other writings of 
Bacon. The prayer at the end of the Thoughts may have been inspired by 
Bacon s invocation of God in his Proemium in The Great Instauration ; 
Diderot s adjuration to young men, take and read, is like Bacon s appeal 
Ad Filios. 5 Critics of Diderot s book, therefore, could have spared them 
selves a number of irrelevant remarks had they realized that Diderot was 
consciously making himself a transmitter of the form and content of the 
Baconian philosophy of science. Diderot, in turn, could have made it easier 
for everyone had he explicitly acknowledged this. But perhaps he was skittish 
after his recent experience with the Journal de Trevoux, which had referred 
maliciously to Bacon s influence on the prospectus of the Encyclopedic. 

In a thoughtful commentary on his friend s work, Grimm noted the 
parallels between Diderot and Bacon: There is the same depth, the same 
breadth, the same abundance of ideas and points of view, the same luminosity 
and sublimity of imagination, the same penetration, the same sagacity, and 
sometimes, for their contemporaries, the same obscurity, especially for 
those with weak sight. 6 And he might have added that they were similar, 
too, in the striking aptness, variety, and vigor of their imagery. A more 
modern and less prejudiced critic has confirmed Grimm s high opinion: 
both Diderot and Bacon, writes Professor Dieckmann, were endowed with 
prodigious scientific imagination, in which the gift of exact observation 
and of realistic vision, the scientific spirit and the spirit of speculation, are 
strangely blended. T 

The influence of Bacon is to be seen particularly in those portions of Diderot s 
book that deal with methodological problems, as well as with descriptions 
or analyses of what should be the attitude of the scientific mind. Bacon, 
not as interested as Diderot in zoology, had no direct influence on the 
part of Interpretation de l& nature that speculates, for example, about the 
origin and differentiation of species, as well as other problems posed by 
the rapidly emerging biological sciences. 8 But as regards general scientific 
method, Bacon insisted upon certain attitudes and predispositions that Diderot 


in his generation also stood for, and that science has learned are indispensable 
prerequisites for progress. The spirit of Bacon was the spirit of observation 
and experimentation. What, it asked, are the facts? And this solicitude for 
the facts was accompanied by a correlative de-emphasis on the preconceived 
and the a priori. Thus Bacon inveighed against the kind of scholasticism 
that contents itself with reading books about nature and trying to discover 
all about her through the use of syllogisms. This scholasticism is easy for 
any age to fall into, so that Diderot in his century, like Bacon in his, wrote 
of the necessity of having knowledge of things. The abstract sciences, wrote 
Diderot, have occupied our best minds too long and with too little fruit. 
Either that which is important to know has not been studied, or no dis 
crimination, insight, or method has been put into one s studies. Words have 
been multiplied endlessly, and the knowledge of things has remained in 

arrears/ 9 

By this emphasis on the knowledge of things, Diderot was implying that 
objects existing outside the mind do partake of objective reality. Wisdom 
therefore lies in the direction of attempting to link human intelligence with 
objective reality. This is, of course, the typical answer given by modern 
science to the problem of reality, the problem of being, and the problem 
of knowledge, namely that external objects are real and that human intel 
ligence can know reality, at least in adumbration, by the study of them. 
There are many other answers that can be made to these ancient philosophical 
problems that the external world has no reality but is simply illusion, or 
that it has reality but the human mind cannot know it, or that the human 
mind can find reality in terms simply and merely of itself, without relating 
mental processes to external objects. As Diderot remarked, unfortunately 
it is easier and shorter to consult oneself than it is to consult nature. Thus 
the reason is inclined to dwell within itself/ Diderot believed it essential to 
link the understanding with outer reality, and he remarked in his Inter 
pretation de la nature: As long as things are only in our understanding, they 
are our opinions; they are notions, which may be true or false, agreed upon 
or contradicted. They take on consistency only by being linked to externally 
existing things. This linking takes place either by means of an uninter 
rupted chain of experiments or by an uninterrupted chain of reasoning that 
is fastened at one end to observation and at the other to experiment; or by 
a chain of experiments, dispersed at intervals between the reasoning, like 
weights along the length of a thread suspended by its two ends. Without 
these weights the thread would become the plaything of the slightest 
agitation occurring in the air/ 10 


According to Diderot, the interpretation of nature can be accomplished 
only by the reciprocal interaction in the mind of the scientist of sense impres 
sion and reflection. He expressed this idea in a much-admired image of the 
bee leaving the hive and returning to it, an image probably derived from 
Bacon: Men have difficulty in realizing how rigorous are the laws for 
the investigation of truth and how limited is the number of our instru 
mentalities. It all reduces itself to going from the senses to reflection and 
back again from reflection to the senses: ceaselessly to turn inward upon 
one s self and to turn outward again. This is the work of the bee: she has 
covered a great deal of territory in vain if she does not come back to the 
hive laden with wax. But she has made a lot of useless piles of wax if she 
does not know how to make a honeycomb out of them. X1 

Greatly as Diderot counted upon the benefits arising from the advancement 
of learning, he did not suppose that advancement to be easy. On the con 
trary, he knew it to be very difficult. It is held back, for one reason, by 
human fallibility; for another, by the rarity of great scientific minds. As to 
the first, he wrote that the understanding has its prejudices, the senses their 
incertitude, the memory its limits, the imagination its glimmerings, instru 
ments their imperfections. Phenomena are infinite, causes are hidden, forms 
are perhaps transitory. Against so many obstacles, both those inside our 
selves and those outside presented by nature, we have only slow experimenta 
tion, only circumscribed reflection. Such are the levers with which philosophy 
proposes to move the world. 3 12 Diderot realized that men capable of manipu 
lating these levers are rare. Being a man of great imagination himself, he 
knew how necessary imagination and creativeness are to the discovery of 
nature s ways. In a passage that describes a man like Louis Pasteur or 
Robert Koch to a tittle, a passage which has been hailed as one of the most 
interesting eighteenth-century attempts to state the problem of genius and 
define what genius is, Diderot wrote: We have three principal means: 
observation of nature, reflection, and experiment. Observation gathers the 
facts, reflection combines them, experiment verifies the result of the com 
bination. It is essential that the observation of nature be assiduous, that re 
flection be profound, and that experimentation be exact. Rarely does one 
see these abilities in combination. And so, creative geniuses are not com 
mon. 13 Such a passage makes it clear that Diderot, in thinking about 
nature, did not content himself with mere empiricism, that is to say with 
the endless accumulation of facts, but insisted on the fecundating nature of 
hypotheses, even incorrect ones. Never is the time spent in interrogating 
nature entirely lost/ he wrote. An important part of his little book arises 


from his understanding of the reciprocal character, of the organic relation 
ship, in the mind of a scientist between his empirical tendencies and his 
non-empirical intuitions. 14 

^Implicit in the Interpretation de la nature are two attitudes very char- 
acteristic l/ of the point of view of the whole eighteenth century. One of these 
attitudes is the distrust of elaborate and comprehensive philosophical sys 
tems. It is quite true that Diderot s aphorisms, like Bacon s, were disjunctive 
and disconnected, but this was intentional. 15 The eighteenth century dis 
trusted the great philosophical summae which, like that of Saint Thomas 
Aquinas in the age of scholasticism or like those of Descartes and Male- 
branche and even Leibniz in the seventeenth century, fitted facts into a 
pattern only too often preconceived. D Alembert remarked in his Pre 
liminary Discourse that the taste for systems, a taste more appropriate for 
flattering the imagination than for enlightening the reason, is today almost 
completely banished from sound treatises, and he gives the credit for it 
to Condillac who, by publishing his Traite des systemes in 1749, had, said 
D Alembert, dealt the taste for systems its decisive blows. 16 The eagerness for 
analysis rather than systematizing and the dislike of revealed authority 
(with the equal dislike of a priori assumptions that had a way of hardening 
into something closely resembling revealed authority) caused Diderot to 
distrust the symmetry and consistency of an elaborate intellectual system 
that more often than not ignored essential facts. As he wrote in the Ency 
clopedic article Philosophic, the systematic spirit is no less injurious to 
the progress of truth. By systematic spirit I do not mean that which links 
truths one to the other in order to form demonstrations, for this is nothing 
but the true philosophical spirit, but I have in mind that spirit that builds 
plans, and forms systems, of the universe to which it consequently desires 
to adjust phenomena willy-nilly. 17 

rThe other respect in which Diderot partook of the general attitude of the 
eighteenth century his influence was so considerable that by accepting 
the attitude he reinforced it was to regard reason more as an instru 
mentality than a thing in itself. Since the eighteenth century plumed itself 
on being the Age of Reason, we may well inquire what that century meant 
by the word. The seventeenth century, with its rationalistic philosophies 
such as Descartes , based on the proposition Cogito, ergo sum could be 
called an age of reason, too but in a very different sense. An important 
semantic change had occurred. Whereas in the seventeenth century reason 
had meant the possession of a number of innate and transcendent ideas, 
much like the highest category of knowledge or reason described by Plato 


in The Republic, the eighteenth century regarded reason as a sort of energy, 
a force, a means by which to do something. It was not so much an essence 
as it .was a process. What the eighteenth century thought reason to be was 
admirably and authoritatively expressed by the late Ernst Cassirer: To it 
reason was no longer an essence of innate ideas, granted anterior to experi 
ence, by which the absolute being of things is disclosed to us. Reason is 
much less a possession than it is a mode of acquisition. Reason is not the 
area, not the treasury of the mind, in which truth, like a minted coin, lies 
protected. Reason is rather the principal and original force of the mind, 
which impels to the discovery of truth and to the defining and assuring of 
it. 18 The whole eighteenth century, he said, conceived of reason in this sense. 

In the Interpretation de la nature Diderot proved himself familiar with 
the scientific discoveries and investigations going on in his day. They, in 
turn, suggested to him the paragraphs of conjectures which are an enumera 
tion of many promising experiments that had occurred to him as remaining 
to be done. 19 For example, proceeding from his knowledge of Benjamin 
Franklin s discoveries, which had been published in 1751 and in French 
translation the following year, he conjectured that there was a close relation 
between electricity and magnetism. 20 Diderot, however, was more of a 
philosopher of science than a scientist, more given to suggesting with quite 
extraordinary flair and insight what could be done than to doing it himself. 
And so he only glimpsed the promised land, staying the while in the wilder 
ness with the Encyclopidie. But he had the imagination to know what 
should be done and yet how difficult it was: Open Franklin s book; leaf 
through the books of the chemists, and you will see what the art of experi 
ment demands in insight, imagination, sagacity, and resourcefulness ; and 
he speaks of the divination that skilled experimenters acquire by which they 
smell out the word he uses is subodorer unknown procedures, new 
experiments, and results previously neglected. 21 

Diderot had caught the scent of a great change that was coming over the 
sciences in his century the change in subject matter from pure mathe 
matics to the natural sciences and the altered intellectual outlook that this 
involved. We are verging upon a great revolution in the sciences, he 
wrote. To judge from the bent that it seems to me minds are showing for 
ethics, belles-lettres, natural history, and experimental physics, I would almost 
venture to say that in less than a hundred years there will not be three 
great geometricians [this is the eighteenth-century word for what we now 
call a researcher in pure mathematics] in Europe. This science will come 
to a full stop at the point where the Bernoullis, the Eulers, Maupertuis, 


Clairaut, Fontaine, D Alembert, and La Grange will have left it. They 
will have set up the columns of Hercules: there will be no going beyond 
that. 22 There is a dash of exaggeration in Diderot he was always just a 
little larger than life and there is exaggeration in this passage, for within 
Diderot s predicted hundred years the German mathematician Gauss had 
opened up new horizons in pure mathematics. Thus Diderot s remark can 
be taken as just another example of the apothegm that prophecy is the most 
gratuitous form of error. Nevertheless, as Cassirer remarked in discussing 
this passage, Diderot was the one among the thinkers of the eighteenth 
century who possessed perhaps the sharpest sense of smell (Spiirsinn) for all 
the intellectual movements and changes of the epoch. 23 His words should 
be taken in the sense of a new and fuller realization of the role to be played 
by the natural sciences, a new and fuller realization that mathematicians 
proceed by logical concepts and axioms that, although they have a rigorous 
self -consistency, possess no direct access to the empirical and concrete actuality 
of things. As Diderot remarked, pure mathematics is a kind of general 
metaphysics in which bodies are stripped of their individual qualities. 24 
He, on the contrary, with his sense of the importance of research into organic 
life, wanted to enlarge scientific method sufficiently to allow for the study 
of these individual qualities. A new ideal of science was growing up calling 
for purely descriptive studies and interpretations of nature. And this ideal, 
wrote Cassirer, Diderot conceived and sketched out in its general char 
acteristics long before it was elaborated in detail. 25 This was the revolution 
that Diderot detected. 

In his early writings Diderot had shown an awareness of the importance 
of biological researches, especially for the new light that they threw upon 
old problems of theology and metaphysics. This interest had been reflected 
in 1746 in the Pensees philosophiques and three years later in the Lettre sur le$ 
aveugles. The supposititious deathbed speech of Saunderson in the Lettre 
sur les aveugles had posed the problem of evolution and the necessity of 
studying process and change in life forms. Therefore, it is not surprising that 
Diderot carries these speculations one step forward in his Interpretation de 
la nature. The recent scientific writings of La Mettrie, of Buffon, and of 
Maupertuis, the president of the Prussian Academy, had provided a spring 
board, for they trenched on the very delicate question delicate, considering 
that Genesis was thought to have decided the issue once for all of the 
origin of life and the origin of species. Diderot took these speculations, espe 
cially those of Maupertuis, and, as Grimm remarked, adroitly adopted the 
policy of refuting the supposed Dr. Baumann [Maupertuis], under the pre- 


text of the dangerous consequences inhering in this opinion, but in reality 
in order to push it as far as it could go. 26 The results may be seen in some 
astonishing passages which read like a preview of the theory of evolution. 27 
These passages, like the one about to be quoted, reveal Diderot as a 
natural scientist who was a leader in introducing ideas of transformism 
into modern scientific thought. Here we have the thinker who was aware 
of time and change, who had an intimation of the role of process in the 
elaboration of organic life, and who grappled with the concepts of the 
dynamic and the genetic. In his attempt to understand and interpret nature, 
Diderot surpassed the merely taxonomic, that part of science that classifies 
and arranges, and showed himself quite scornful of scientists like Linnaeus, 
whom he called a methodist. 28 In contrast, Diderot sought to understand 
the functional and investigate the process of change itself. Diderot, wrote 
Cassirer, was one of the first to surmount the static eighteenth-century 
picture of the world and substitute for it a clear-cut dynamic one. 29 But 
whenever one begins to think, as Diderot did, in terms of concepts in which 
time and the changes brought about by time make all the difference- 
process, adaptation, development one needs a new kind of logic to sup 
plement the old logic of the Aristotelian syllogism, which takes no account 
of time. Diderot was a precursor of the nineteenth-century philosophers 
and scientists who, following Hegel, adopted the mode of logic represented 
by the dialectic of thesis, antithesis, and synthesis. Marxist writers in par 
ticular are appreciative of the dialectical character of Diderot s thought. 
Karl Marx himself once referred to Diderot as his favorite prose writer, and 
Henri Lefebvre, one of the most influential Marxist intellectuals in France 
today, declares that the importance of the Pensees sur ^interpretation de la 
nature in the history of the philosophy of sciences, of science itself, and of 
human thought, cannot be overestimated. 30 The following passage is de 
scribed by Lefebvre as one of real genius and truly revolutionary. It was 
also one in which Diderot, somewhat masking the boldness of his thought, 
deemed it prudent to pretend to doff his hat to Genesis : 

May it not be that, just as an individual organism in the animal or vegetable 
kingdom comes into being, grows, reaches maturity, perishes and disappears from 
view, so whole species may pass through similar stages? If the faith had not taught 
us that the animals came from the hands of the Creator just such as they are now, 
and if it were permissible to have the least uncertainty about their beginning and 
their end, might not the philosopher, left to his own conjectures, suspect that the 
animal world has from eternity had its separate elements confusedly scattered 


through the mass of matter; that it finally came about that these elements united 
simply because it was possible for them to unite; that the embryo thus formed 
has passed through an infinite number of successive organizations and develop 
ments; that it has acquired in turn movement, sensation, ideas, thought, reflec 
tion, conscience, sentiments, passions signs, gestures, sounds, articulate speech, 
language laws, science and arts; that millions of years have elapsed between each 
of these developments; that there are perhaps still new developments to take place 
which are as yet unknown to us; that there has been or is to be a stationary condition 
of things; that the being thus developed is passing out of, or will pass out of, that 
condition by a continual process of decline, in which his faculties will gradually 
leave him just as they originally came to him; and that he will finally disappear 
from nature forever, or rather, will continue to exist, but in a form and with 
faculties wholly unlike those which characterize him in this moment of time? 
But religion spares us many wanderings and much labor. If it had not enlightened 
us on the origin of the world and the universal system of beings, how many dif 
ferent hypotheses would we not have been tempted to take for nature s secret? ai 

Of this passage it has been remarked that there is contained within it *not 
only the transformation of species, but also the sketch of a complete system 
of materialistic and ateleological evolutional philosophy, after the Spencerian 
fashion. 32 

On the face of it, Diderot s Interpretation de la nature does not appear 
very antireligious. Nor should one expect it to appear so, for, after all, it 
had been published by tacit permission and had been approved by a censor, 
even though published without the king s license. Upon examination, how 
ever, it can be seen that Diderot was, as usual, trying to open up channels 
for freer thought, and was consequently challenging established attitudes 
and modes of thinking as much as he dared. No doubt he intended that 
the very epigraph of the book an apt quotation from Lucretius poem 
De rerum natura, Those things that are in the light we behold from the 
darkness * should by association remind his readers that Lucretius 
avowed purpose was to free mankind, crushed, as he said, beneath the 
weight of religion. Moreover, Diderot s popularizing of Bacon, though in 
telligent and necessary, was also provocative, as can be demonstrated by the 
fact that years later the able and distinguished Catholic conservative, Joseph 
de Maistre (1753-1821), in books like Les Soirees de Saint-Peter sbourg, de 
voted much attention to singling out and attacking Bacon as the prime 
originator of what De Maistre regarded as the going-wrong of the eighteenth 
century. Finally, Diderot s transformist* views, such as those quoted above, 

* Quae sunt in luce tuemur e tenebris. 



in combination with Ms theory that all atoms, even in non-organic matter, 
have some sort of sensitivity -a view already apparent in the Interpretation 
de la nature and destined to bulk ever greater in his thought - moved him 
very close to a materialistic view of the universe. 33 

Although the Mercure dc France and the Journal Encyclopedique spoke 
favorably of the Interpretation de la nature, on the whole it did not meet 
with a very enthusiastic reception. 34 Reviewers usually complained that it 
was obscure. The Abbe" Raynal referred in his news letter to the fact that 
there were only four metaphysicians left in France - Buffon, Diderot, 
Maupertuis, and CondiUac. The second has strewn about in two or three 
brochures, some quite acute ideas, but he has only insights without having 
any system and without developing their relationships. 35 The journalist 
CMment remarked of Diderot, What a pity that ... [he] should be so 
marvelously, so bristlingly, so desperately, metaphysical! You are about to 
see his Penstcs sur I interpretation de la nature; at one time it is a murky 
verbiage as frivolous as it is learned, at another an erroneous sequence of 
desultory reflections, the last of which proceeds to get itself lost a hundred 
leagues off to the left of the first. Only when he gets trivial does he become 
almost intelligible. But if you have the courage to follow him gropingly 
into his cavern, from time to time it may light up with some illuminating 
gleams. . . . 36 Frederick the Great, who disliked Diderot, remarked apropos 
of the adjuration Young man, take and read, There is a book that I shall 
not read. It s not written for me, for I m an old fogy. His continuing ill 
will can probably be detected in the fact that a Berlin newspaper, in a 
I773 review of a collected edition of Diderot s works, said of the Inter 
pretation de la nature that it was a sublime rigmarole in which the author, 
always in the clouds, contemplates phantoms which he takes for nature. 3T 
And La Harpe, a one-time philosophe who later turned against them, wrote 
about 1799, having had some forty-five years in which to think up the 
epigram, that never has nature been more hidden than when Diderot made 
himself her interpreter. 38 

The most painful contemporary review appeared as the leading article 
in the first number of the new Parisian periodical Annee Litteraire. The 
position given to the review symbolized the editorial policy of the Annee 
Litteraire for the next thirty years: it was always ready to focus its critical 
attention upon the ideas of the philosophes. The editor, a former Jesuit 
named Freron (1719-76), proved himself a doughty and formidable ad 
versary of the philosophes, and they retaliated by speaking of him as if 


he were the vilest of men. Voltaire, particularly, made him the butt of 
numerous jibes, a famous one being: 

They say a snake the other day 
Bit Freron as in sleep he lay. 
What think you did thereon betide? 
Not Freron, but the serpent, died. 39 * 

In reality Freron conducted his magazine with both skill and urbanity, a 
stalwart and hard-hitting conservative but an independent one. 40 More 
over, his journal was prodigiously successful as widely read as the Journal 
des S$avans and more widely read than the Jesuit Journal de Trevoux.^ In 
March 1754, Freron presented the Annee Littcraire to the public, and his 
remarks about Diderot s little book provided the basis for a long and hearty 
mutual disesteem. After criticizing the prideful presumption* of the philo- 
sophes in general, he turned to Diderot. The author is perhaps a great 
genius; but this astral body is always covered with the clouds of an im 
penetrable metaphysics. . . . Although I do not at all understand what he 
was trying to say, I feel that there must be a way of expressing himself more 
clearly, and that the confusion of his words comes merely from that of 
Eis mind. Freron went on with his animadversions, not forgetting to 
envenom the quarrel between Diderot and Reaumur by meticulously quoting 
some unfair and ungracious remarks that Diderot had made concerning the 
great entomologist. 42 Most of all, Freron objected to the praise that Diderot 
lavished on his friends and the epithets he showered upon his enemies. 
They [Diderot and his friends] render one another these little services. 
They are associated with certain others for this traffic in incense. These 
Philosophical Powers have concluded among themselves an offensive and 
defensive alliance. 5 43 

Freron was confident that the author of the Interpretation dc la nature 
would not be esteemed by posterity. In this prediction Freron was too sure 
of himself, for posterity finds in Diderot s views on science a greater pene 
tration and spaciousness than many of his contemporaries could appreciate. 
And with it all is a marked desire on Diderot s part to make science useful 
and to make it understood by the people. First and last, Diderot was a man 
who sought the popularization and application of knowledge, and it was 

* L autre jour, au fond d un vallon, 
Un serpent mordit Jean Freron. 
Que pensez-vous qu il arriva? 
Ce fut le serpent qui creva. 


this desire within him that made him a man of potent action as well as a 
man of potent thought. Let us hasten/ he wrote, to make philosophy popular. 
If we want the philosophers to march on, let us bring the people up to the 
point where the philosophers are now/ 44 And along with his desire to 
make science useful Besides, the useful circumscribes all 45 Diderot 
breathed into his little book a Baconian humbleness toward nature, a 
feeling, as Bacon had put it, that we cannot command nature except by 
obeying her. 

Diderot was sometimes humble but not often meek. In the face of the 
criticism that he evidently anticipated, he descanted in the Interpretation 
de la nature upon the obstacles besetting a researcher. Like many of Diderot s 
most eloquent pages, it is somewhat tinged with a trace of self-pity and 
self-praise. Still, it is a moving passage: 46 

... he who resolves to apply himself to the study of philosophy may expect not 
only the physical obstacles that are in the nature of his subject, but also the multi 
tude of moral obstacles that will present themselves, as they have done to all the 
philosophers preceding him. When, then, it shall come about that he is frustrated, 
misunderstood, calumniated, compromised, and torn into pieces, let him learn 
to say to himself, Is it in my century only, am I the only one against whom there 
are men filled with ignorance and rancour, souls eaten by envy, heads troubled 
by superstition? ... I am, then, certain to obtain, some day, the only applause 
by which I set any store, if I have been fortunate enough to merit it. 


Man Is Born To Think for Himself 


IHE suspension of the Encyclopedic in February 
1752 occurred only a few days after the publication 
of its second volume, not unnaturally causing people to be more concerned 
with the decision regarding the future of the venture than with the con 
tents of the book. A close examination of Volume II, however, evidently con 
vinced readers, as it had convinced the censor Lassone, that the work was 
carrying out its initial promise, and no doubt this impression contributed 
affirmatively to the decision to allow continuation of the work. Representa 
tive of some of the more important articles in its 871 double-columned folio 
pages were those on Ballet 5 by Cahusac, soon to publish his authoritative 
Dansc antienne et moderns; Barometer by D Alembert; Sundials (Cadran) 
by D Alembert and Diderot, a throwback to the latter s mathematical days; 
and, by Diderot, Stockings (Bas), Bronze/ Cacao, 5 Wood (Bois, show 
ing his interest in forestry), Brewing (Brasserie), Printing Characters 
(Caracteres d imprimerie), and Playing Cards (Cartes), to give a sampling 
of his many and varied articles. Something of the self-respect of the middle 
class is to be seen in the editors remark concerning the article on Brewing : 
"Brewing" is based upon a memorandum by M. Longchamp, whom a con 
siderable fortune and much aptitude for letters has not detached from the 
occupation of his ancestors. x And it is of interest to find Diderot saying in 
the article on Stockings/ I worked in M. Barrat s shop, the foremost crafts 
man of his kind and perhaps the last whom one will find of equal skill. 2 
Indeed, as Diderot had claimed in his prospectus and D Alembert had re 
iterated in the Preliminary Discourse/ Diderot went to a great deal of trouble 
to familiarize himself with the construction and operation of machines. 3 
Naigeon says that Diderot had scale models of the machine for knitting 
stockings and the machine for making cut velvet. Several times I have 
discovered him in his study intentionally dismantling the one or the other, 



in order to put it together again in a working condition, an operation which 
he executed with an ease betokening a pretty lengthy study of the art, its 
means of achieving its ends, and its results. 4 

Throughout Volume II, as in Volume I, there continued to be an impatience 
with vulgar errors, as in the article Boa for instance. Diderot recounts, in 
order to show how far exaggeration can go, that some authors had set forth 
that a boa can swallow an ox: Historians are ordinarily the opposite of the 
mountain in labor. If it s a matter of a mouse, their pen gives birth to an 
elephant. There was the same eagerness for innovation and improvement, as 
when in the article Canvas (Canems) Diderot wrote, We are here going 
to propose a sort of canvas that will make embroidery, whether done m 
wool or in silk, infinitely more beautiful, less lengthy, and less costly. There 
was the same provocation of enemies, as when Diderot again twitted the 
Franciscans, in Cafztchon, on the scholastic subtleties of their Duns Scotus; 
the same disconcerting juxtaposition of actual facts with Scriptural fantasies 
as when Diderot contrasted the positive exploits of the Basque whalers with 
the defeatist quotation from Job, And are you able to pull up Leviathan with 
a hook? 7 There was the same nagging at articles of Christian faith, as when, 
in the article Caucasus, Diderot quoted the ancient geographer Strabo to 
the effect that the Caucasians put on mourning when children were born and 
rejoiced at their funerals. There is no Christian thoroughly penetrated with 
the verities of his religion who ought not to imitate the inhabitant of the 
Caucasus and congratulate himself upon the death of his children. Death 
assures the newborn child of an eternal felicity, while the fate of the man 
who appears to have lived the most holy life still remains uncertain. How 
our religion is at once both terrible and consoling! 8 And there is Diderot s 
usual interest in matters having to do with anatomy, physiology, and medi 
cine. The conservation of men and progress in the art of healing them, he 
wrote in the article Cadaver, are objects so important that in a well-ordered 
state the priests would receive cadavers only from the hands of the anatomist 
and there would be a law forbidding the inhumation of a body before it was 
opened. How many phenomena are unsuspected and will always be un 
known because it is only by frequent dissection of cadavers that they can 
be learned. Diderot was consistent in this view, for before his death he 
left instructions that an autopsy be performed upon him. And the last sentence 
of his article Cadaver could be interpreted as making him one of the early 
proponents of a program of public health and preventive medicine: The 
conservation of life is an object that individuals adequately concern them 
selves with, but that it seems to me society neglects too much. 9 


Though it waited until the appearance of Volume III, the Journal des 
Sgavans finally praised Volume II. This periodical, it will be remembered, 
had enraged D Alembert by alleging that his Preliminary Discourse had an 
antireligious tendentiousness. The editors had meanwhile made amends 
by praising his Melanges de literature, d histoire et de philosophic, a move 
thought by some to be an attempt, although an unsuccessful one, to split 
D Alembert and Diderot. 10 Now, belatedly, the Journal paid both volumes 
some very flattering attention. 11 

In addition to acknowledging the anonymous help of D Holbach, the 
editors of the Encyclopedic were also able to announce in their Foreword 
to Volume II that BufEon had consented to contribute the article Nature. 
This was a feather in their cap: the Encyclopedic was beginning to obtain 
the services of great names. It is true that by the time the volume including 
*N* was published, conditions had changed and so had Buffon, but for the 
nonce it was something to boast about. 

The Chevalier Louis de Jaucourt was also announced as a new contributor. 
This man, who belonged to one of the oldest families in France, came to 
be of truly inestimable value to the enterprise. Unlike most members of the 
upper nobility, he had been carefully and broadly educated. While still a 
child, he was sent to Geneva and emerged from his training there a Protes 
tant, a very latitudinarian and undogmatic one. It is, incidentally, a phe 
nomenon of more than trivial interest that in Diderot s milieu there were 
so many Protestants or men of Protestant origin, like Grimm or De Jaucourt 
or, later, Meister -just as it is interesting to see how receptive he was to 
foreign influences, especially English, German, and Italian. This catholic 
and cosmopolitan urbanity has often been made a matter of reproach to 
Diderot on the part of nationalistically minded French critics, but these Prot 
estant and foreign associations kept the windows open and prevented him 
from feeling stifled in the French society of his day, with all its unyielding 
and absolutistic tendencies. 

Following his years in Geneva, De Jaucourt spent three years at Cambridge 
and then at Leyden, where he studied under the celebrated Boerhaave, was 
a fellow-student of Dr. Theodore Tronchin, and became a doctor of medicine. 
In 1736, at the age of thirty-two De Jaucourt was nine years older than 
Diderot he returned to Paris. The breadth of this training, combined with 
his unusual knowledge of languages, made him one of the most highly re 
spected polygraphs of the century, and it was appropriate that he became 
a member of a number of foreign academies. Besides all these qualifications, 
he was a man of singular purity and uprightness, qualities of the greatest value 


to the Encyclopedic, especially as many were only too inclined to think that 
the work was edited by sinister and immoral men. 12 

As volume succeeded volume, De Jaucourt tended to take over the multitude 
of short articles on every conceivable subject that Diderot himself had done 
in the early days of the work; especially following the Great Desertion in 
1759, De Jaucourt s symbol D. J. was seen on almost every page of the last 
ten volumes. De Jaucourt was a great scissors-and-paste man and, because 
he frequently failed to mention his sources, can legitimately be regarded as 
the Encyclopedias champion magpie. His intellect was not creative, but it 
was retentive, dogged, and quite accurate. His was a truly encyclopedic mind, 
in the quiz-program sense of the word, and while it is easy to scorn such 
talents, as Diderot himself was inclined to do, it ought never to be forgotten 
that it was the modest and unpretentious De Jaucourt who was as responsible 
as anyone for making the Encyclopedic the great focal point and gathering 
place of factual inf ormation. 

It has become a truism that the Encyclopedic was of transcendent importance 
in transmuting values and changing the outlook of the eighteenth century. 
According to a present-day French critic, the Encyclopedic was the meta 
phor is interesting and suggestive the turntable of the epoch. 13 The new 
conception of the world and man that it propounded came as a result not 
only of following out the scientific and metaphysical implications of the 
sensistic psychology, but also from making new assumptions about the 
origins of man and society. There could be pieced together from the Ency 
clopedicit was not safe to be too explicit upon subjects so delicate an 
explanation of the nature of man and the beginnings of society that did 
not depend upon Genesis, an explanation of history and its meaning differing 
from that described in the Old and New Testaments and Saint Augustine s 
City of God. The new sociology and the new social science if they can 
be dignified at this early period with such positive names, so tentative and 
groping were their beginnings depended upon a view of man and society 
that of course differed from the traditional and authoritarian one. It can 
be bluntly described as the difference between conceiving of man and society 
as an act of creation and conceiving of them as the consequence of growth. 
The Encyclopedic view was the naturalistic view. The intimations and 
affirmations of it, traceable in numerous articles in the Encyclopedic, would 
amply repay the further researches of historians of the social sciences. 14 

This new and positivistic approach, which was to command the whole 
hearted admiration of Auguste Comte, the founder of sociology, was in 
conflict, potentially or overtly, with established views, and continuously in 


danger of encountering some form of attempted suppression. On the prin 
ciple, then, of always keeping one s opponent a little off balance, the Ency 
clopedic seldom overlooked an opportunity to sow doubt concerning Chris- 
dan evidences, and Volume II followed this rule. Diderot s article on The 
Bible outlined a complete scheme of exegetics, according to one critic. 
Another has remarked of this article that, by posing a whole host of exegetical 
questions, Diderot undermined the principle of the verbal inspiration of 
the Bible once for all. 15 He continued to make a display of these exegetical 
principles in his article on Old Testament Canon (Canon, en theologie), 
an article of such erudition that it is one of the sources for supposing his 
theological studies had been carried to an advanced stage. He also suggested, 
rather gingerly, some telling criticisms of the institution of celibacy in 
Celibat, and the long article on Certitude, contributed by the Abbe de 
Prades and no doubt written in good faith, manages in its examination of 
the credibility of miracles to be more unsettling than reassuring. Little 
can be found in the Encyclopedic that directly challenges prevailing and 
official doctrine, but there is much that raises doubt while professing to allay it. 
A chance remark hidden away in a very long article in Volume II stirred 
up a storm of antagonistic derision against the Encyclopedic. The offending 
phrase was in the article devoted to Deer (Cerf). Diderot probably did 
not write it the author was probably Charles-Georges Le Roy, Superin 
tendent of the Chase in the Royal Park at Versailles but he made himself 
doubly responsible by printing it with an asterisk, and the incident shows, 
if nothing else, how closely the Encyclopedic was scrutinized by its enemies. 
Although the subject would appeal primarily to sportsmen, an important 
part of the article and this is characteristic of the Encyclopedic was de 
voted to a discussion of embryology, with references to Maupertuis book 
Venus physique and to the observations on the embryos of deer made by 
William Harvey, the discoverer of the circulation of the blood. But what 
excited the scorn and indignation of Diderot s enemies was the statement 
that many marvelous things are told about deer, especially when they have 
attained the age of reason! 16 One might suppose that this faintly ludicrous 
statement, the lucubration no doubt of a deer lover, was harmless enough. 
But actually it touched one of the exposed nerves of the eighteenth century, 
for the view that animals are automata and consequently without reason 
had become a matter of dogmatic religious belief in France. Descartes had 
asserted this in his Discourse on Method, arguing that all that animals dis 
play in their response to situations is a mechanical reaction set up by the 
vibration of fibers. This makes the brute soul a materialistic one; church- 


men insisted upon making an absolute distinction between man and animals, 
the former, of course, having a soul untouched by materialism. 17 Here was 
still another impediment to free inquiry, for it thus became impious^to 
make any conclusions about human psychology based upon animal analogies. 
Pavlov s dogs are an example of the fact that much can be learned about 
human psychology from animal behavior, but in the eighteenth century 
this channel of inquiry was almost wholly blocked. Diderot, as usual, was 
willing to dare for the sake of intellectual freedom by letting the remark 
pass about deer s attaining the age of reason and, more importantly, by 
presenting the pros and cons in the article entitled Bite, animal brute. 
Here he remarked that to assert that they have no soul and that they do 
not think is to reduce them to the status of machines, which one seems 
scarcely more authorized to do than to declare that a man whose language 
we do not understand is an automaton. 18 

Included in this same volume was an article by Diderot that was an 
original contribution to aesthetics, and which has received a great deal of 
serious attention from specialists in that branch of philosophy. 19 This was 
the article on The Beautiful (Beau). An unobtrusive essay, it summed up 
and criticized previous attempts to analyze the nature of beauty and then 
went on to break new ground by stating Diderot s conceptions. Here,^ there 
fore, is an excellent example of the function served by die Encyclopedic in 
the intellectual life of the eighteenth century. Not only did it assemble the 
accumulated facts of a couple of millennia, not only did it describe the me 
chanical arts and crafts as had never been done before, not only did it 
earnestly advocate new modes of thought in psychology and social phi 
losophy, but it also had a contribution to make in matters involving art. 
Thus the universality of the Encyclopedic is further exemplified, as also 
the versatility and creative vigor of Diderot, who could strike off so sub 
stantial a piece just to satisfy the routine requirements of the Encyclopedic. 
Diderot began by summarizing and discussing recent analyses of the nature 
of beauty, especially those of the Englishman Francis Hutcheson. Then, 
having criticized these views, he began to state his own. He disagreed with 
Hutcheson, who thought that we have an internal sense of beauty, which, 
operating somewhat like an innate idea of God or morality, informs us 
of what is beautiful and what is not. Diderot s own theory is so simple 
that at first it seems slight. He declared that the perception of relationships 
is the basis of the beautiful. 20 In another article, on Beauty (Beautf), he 
wrote, But I think that, philosophically speaking, everything that excites 
in us the perception of relationships is beautiful. 21 


At first blush the definition of the beautiful as a perception of relation 
ships may seem, intolerably superficial. But as a matter of fact it allows 
ample latitude for the development of connoisseurship and taste. The more 
sensitive and perceptive the artist or the contemplator of art, the more re 
lationships he perceives and the finer and more reliable will be his criteria 
of beauty. The artist or the connoisseur becomes like the skillful experimenter 
Diderot alluded to in his Interpretation de la nature he develops a feel 
for his subject, he smells it out. 

Diderot s doctrine that our sense of the beautiful depends upon our per 
ception of relationships is characteristic of his thought, which always dem 
onstrated flexibility, relativism, and a sense of the importance of context. 
Diderot rebelled against authoritarianism as much in matters of artistic ap 
preciation as in matters of religious belief. He was, in terms of the dispute 
that convulsed French letters in the closing years of the seventeenth century, 
more a Modern than an Ancient. Although he did not specifically allude to 
this famous quarrel in his Encyclopedic article, by denying that there is such 
a thing as Absolute Beauty he quite clearly attacked the traditionalist posi 
tion of Boileau, the Ancients principal defender. In accord with this line 
of reasoning, Diderot pointed out that a line in a play might be tragic in 
one context, deliciously comic in another. 22 Conditions, circumstances, and 
contexts determine our appreciation of beauty, he wrote, thus emphasizing, 
as modern aestheticians have noted, the infinitely conditional character of 
the esthetic experience. 23 

Any theory of the beautiful rests upon a psychological doctrine of how the 
mind works in perceiving beauty. Diderot again applied the sensistic doc 
trine of John Locke: Whatever the sublime expressions used to designate 
the abstract notions of order, proportion, relationships, harmony called, 
if one likes, the eternal, original, sovereign, essential rules of beauty they 
have passed by way of our senses in order to reach our understanding. . . . 
These remarks are a positive way of restating Diderot s denial of an internal 
and absolute sense of beauty. And they show how his conception of the 
understanding of beauty resembles his understanding of nature in Inter 
pretation de la nature. Both the artist and the scientist must seek for reality 
in the external world. The scientist cannot discover truth by simply follow 
ing reason within the recesses of his mind, just as the artist or connoisseur 
cannot find beauty by that process. Therefore/ wrote Diderot, I call beauti 
ful everything outside me containing in itself the material for awakening 
in my understanding the idea of relationships; and [I call] beautiful in 
regard to myself everything that awakens this idea. . . . Whence it follows 


that, although there is no absolute beauty, there are two sorts of the beautiful 
in relation to us, a red beauty and a perceived beauty 24 

Diderot believed human beings so constituted that the appreciation of 
relationships and therefore, by his definition, the appreciation of beauty 
was natural to them. The nature of man makes him conscious of the 
relationships upon which beauty depends. It is as fundamental as that. Man s 
mind by its nature seeks symmetry, order, proportion, harmony, which is 
tantamount to saying that it seeks the evidence of relationships and is pleased 
by them. Moreover, in Diderot s view, beauty is a reality. Whatever may 
result from all these causes of diversity in our judgments, this is by no 
means a reason for thinking that real beauty, that which consists in the per 
ceiving of relationships, is a chimera. The application of this principle may 
vary to infinity, and its accidental modifications occasion dissertations and 
literary wars; but the principle remains none the less constant/ 25 

Diderot s theory of the beautiful allows for an infinity of nuances and 
gradations, and this was like him, too. Diderot was always aware of the 
shadings and paradoxes and ambiguities with which all of human experi 
ence is interwoven. 26 Therefore he responded unfavorably to absolutist defi 
nitions, to descriptions of experience in terms of black and white. It is 
this disposition of mind that entities his thought to be called dialectical 
always qualifying itself, always in a dialogue with itself. This mental dis 
position makes him a thinker, an artist, a critic, very hard to pigeonhole. 

By his emphasis on the relative in the appreciation of the beautiful, 
Diderot inevitably raised the question of taste. For taste is inherently sub 
jective, necessarily depending upon the judgment and appreciation of the 
person contemplating the art object, and thus varies widely, as Diderot 
realized. Everyone agrees/ he wrote, that there is a beautiful, that it is the 
result of perceived relationships; but according as one has more or less 
knowledge, experience, practice in judging, meditating, seeing, plus natural 
reach of the mind, one says that a certain object is poor or rich, confused or 
sustained, paltry or overcharged. 27 It is the difference between the apprecia 
tion of a painting by Rouault and of a calendar picturing a girl with her 
skirt caught in a wringer. 

The problem of taste brings us back to the problem of standards in judg 
ment. If there is no absolute beauty, are there then no criteria to go by? 
Must the appreciation of beauty become, after all, purely anarchical, with 
everybody complacently belonging to the I-don t-know-art-but-I-know-what- 
I-like school? Diderot was well aware of this problem, as we have seen, 
and in later works, when he discussed what is meant by the imitation of 


nature and spoke of the line of beauty, the ideal line/ he made trenchant 
attempts to deal with it. 28 Those who are critical of his article on The 
Beautiful usually argue that his doctrine is vague and inconclusive in the 
matter of exploring the relationship of beauty and taste. Perhaps Diderot 
was attempting to deal with the problem rather too much in terms of mere 
logic. At all events, we later find him learning to judge art more in terms 
of techniques than in relationships. Still, his analysis in the article concerning 
the beautiful was a vigorous statement. And it is not to be forgotten that 
he insisted that there is such a thing as objective beauty. Not absolute beauty, 
or beauty to be apperceived by absolute rules. Rather, Diderot s is the at 
titude of a man who, by an understanding of the relative, hopes to approach 
the absolute, yet knowing all the while that the absolute cannot be reached 
and knowing, too, that we should not want to reach it if we could. Per 
haps this defines a liberal, whatever the object of his meditations and 
wherever and whenever he may be found. 


When Volume III of the Encyclopedic finally appeared in November 1753 
after a year and a half of suspension, it contained an important preliminary 
notice written by D Alembert in the name of the editors. The eagerness that 
has been shown for the continuation of this Dictionary/ he began, is the 
sole motive that could have induced us to take it up again. In this moment 
of triumph, D Alembert tended to allow his self-love to prevail, and the 
foreword is replete with a strange combination of apologetics, vainglory, 
and that irritating self-righteousness that the antagonists of the philosophy 
found so exasperating. 29 

D Alembert not unnaturally used the occasion for a restatement of the 
Encyclopedias editorial doctrines. As has previously been remarked, Diderot 
and D Alembert apparently were permitted to recontinue their work without 
having to compromise their principles. It is interesting to observe, as Grimm 
pointed out, that they had not even been required to tip any revised pages 
into the preceding volumes. 30 Their independence would seem to be con 
firmed by D Alembert s statement in the foreword that it is principally by 
the philosophical spirit that we seek to distinguish this Dictionary. Thus 
the Encyclopedic would not contain, he wrote, the lives of the saints nor the 
genealogical trees of ruling houses nor the detailed description of every 
village; nor the conquerors who have devastated the earth, but the im 
mortal geniuses who have enlightened it; nor, finally, a crowd of sovereigns 
whom history should have proscribed. Not even the names of princes and 
grandees have a right to be in the Encyclopedic, except by the good they 


have done the sciences. For the Encyclopedic owes everything to talents, 
nothing to titles, and is the history of the human spirit and not of the 
vanity of men/ And then, with that yearning for a secular immortality so 
characteristic of men who deny heaven and hell, he wrote, May posterity 
love us as men of virtue, if it does not esteem us as men of letters! 31 

Volume III, which ran to nine hundred pages and yet covered the alphabet 
only from CHA to CONSECRATION, began to develop some new de 
partments or areas of interest. One was that devoted to business and business 
practices. Excellent articles, such as Exchange (Change}, Commerce/ and 
Competition (Concurrence], were contributed anonymously by an econ 
omist named Forbonnais. His articles reflect the middle class, businessman s 
point of view characteristic of the whole Encyclopidie?* Another new de 
velopment was the description of legal and administrative institutions (for 
example, various courts, councils, codes, and officers, such as Chancellor* 
and Commissioners ). These numerous articles were the work of the lawyer 
and legal antiquarian Boucher d Argis (1708-91), the recipient of special 
editorial thanks in the forewords to Volumes III and IV. These multi 
tudinous articles, which greatly increased the bulk of the work, were in 
formative, authoritative, and dispassionate; and they gave the Encyclopedic 
a less contentious complexion than it had had in the first two volumes. 
Unquestionably they contributed greatly to the value of Volume III and its 
successors. It is already acknowledged, wrote Clement six weeks after the 
publication of the third volume, that it is superior to the second, which 
in turn surpassed the first. 5 33 

Diderot made fewer contributions to Volume III than to previous volumes, 
but the articles were substantial. There were the usual ones concerning the 
crafts, such as Tost Chaise (Chaise de paste), Hemp (Chanvre}, and Hat* 
(Chapeau). There was the usual call for reforms, as when, in the article 
on Hunting (Chasse), he wrote of the damage done to crops and the 
savage punishments dealt out to poachers. If the life of a man is worth more 
than that of all stags, why punish a man with death for having made an 
attempt upon the life of a stag? 34 Similarly, Diderot s remarks on the 
importance of actors (Comediens) are interesting as testimony to his faith 
in the social value of the theater and to his desire to secure to actors their 
civil rights. If one considers, he wrote, the purpose of our theater and 
the talents necessary to a person for successfully playing a role in it, the 
position of an actor will necessarily assume in every right mind the degree 
of consideration that is its due. It is now a matter, especially on our French 
stage, of inciting to virtue, inspiring horror of vice, and exposing that which 


is ridiculous. ... In spite of which, they [actors] have been severely treated 
by some of our laws. . . . 35 Diderot s own plays, written a few years later, 
exemplified this conviction that the theater could incite to virtue. Corre 
spondingly, he always esteemed actors highly as the archpriests of what may 
be termed a secular church. 

Particularly interesting, because it exemplified Diderot s versatility and 
adaptability, is the article on Composition in Painting. As Diderot later 
told the story, we had hoped to have from one of our most vaunted 
amateurs the article "Composition in Painting." We received from him a 
couple of lines of definition, without exactness, without style, and without 
ideas, with the humiliating confession that he knew no more about it; and 
I was obliged to write the article, I who am neither a connoisseur nor a 
painter. 36 In this article (which dealt with such subjects as the unity of 
time, place, and action in painting; the treatment of draperies; the sub 
ordination of figures; etc.), the reader will find many o the ideas that 
Diderot set forth years later in his Salons. His article was full of fresh and 
striking suggestions, and one great French critic, usually austere in his 
praise, wrote, This article is delicious. . . . Lessing s whole Laocoon [1766] 
is in it in substance. 37 

The usual campaign of sowing doubts in regard to revealed religion was 
waged in Volume III. The delicate and tricky but inescapable subject of 
religion posed a truly Hamlet-like dilemma. Diderot solved the problem, 
sometimes at the price of his intellectual honesty, by never refusing lip 
service to the claims of revealed religion. But his treatment of such subjects 
as Christianity, The Chaldeans, Chaos, and Sacred Chronology (all of 
them lengthy and important articles appearing in Volume III), while super 
ficially unexceptionable, was apt to raise doubts and lead to ambiguous 
conclusions. It became a favorite tactic of the Encyclopedic to indulge in 
chronological calculations affecting the Old Testament, for the Scriptures 
were demonstrably confusing and inconsistent, so that the thin wedge of 
higher criticism could most easily enter at this point. The article on The 
Chaldeans, considering their proficiency in astronomy, gave Diderot an 
obvious opportunity; and in his article on sacred chronology, he discussed 
and compared various chronological systems, threw doubt on the accuracy 
of Old Testament manuscripts, referred learnedly to Samaritan texts and 
to the Septuagint, and inclined toward the conclusion reached by the Abbe 
de Prades except that it would be impermissible to adopt it, now that 
the censures of several bishops of France and the Faculty of Theology have 
declared it prejudicial to the authority of the sacred books. Diderot con- 


eluded this article abruptly, perhaps for the very purpose of leaving the 
reader uncertain and in the air. The article on Chaos/ too, was singularly 
and probably intentionally as chaotic as the subject it dealt with. It 
posed all sorts of difficult logical questions regarding the Creation, sum 
marized with loving care the objections of Spinozists and materialists (while 
purporting, of course, to refute them), and concluded by leaving the ques 
tion in a perplexing and confused condition. 38 The article on Christianity* 
was similarly tendentious. Instead of analyzing Christianity as a spiritual 
religion, it somehow managed to discuss it as if its principal importance 
had been as an instrument of government. Diderot plainly implied, to use 
Gibbon s famous phrase, that all forms of religion are regarded as equally 
true by the people, equally false by philosophers, and equally useful by 
magistrates. Accordingly he had the audacity, in eighteenth-century France, 
to suggest that Mohammedanism and Christianity had many points of re 
semblance; he quoted Montesquieu copiously; and altogether was not far 
short of adumbrating the sociology of religion. 

What the philosophes meant by philosophy is admirably exemplified 
by two quotations from articles that Diderot wrote for Volume III. The 
first one reveals their characteristic hatred of priestcraft and their high, 
humanistic views of the nature of man. Discussing the Chaldeans, Diderot 
wrote, in transparent allusion to authoritarian beliefs anywhere, that one 
must be oneself very little of a philosopher not to feel that the finest privilege 
of our reason consists in not believing anything by the impulsion of a 
blind and mechanical instinct, and that it is to dishonor reason to put it 
in bonds as the Chaldeans did. Man is born to think for himself. S9 * 

The second quotation is more Rabelaisian but equally philosophical/ In 
the article on Heat* (Chaleur) Diderot discussed the periodicity of the 
sex impulse in animals, and then compared it with that of a human being. 
It appears that the frequency of its accesses [in man], which begin with 
his adolescence and last as long and longer than his capabilities, is one of the 
consequences of his ability to think and of his suddenly recalling to himself 
certain agreeable sensations .... If this is so, the lady who said that if 
animals made love only at intervals, it was because they were beasts [this 
is a pun: betes means both beasts and stupid ], made a more philosophical 
remark than she realized/ 40 

The most controversial article in Volume III turned out to be one by 
D Alembert on the quality of education in the secondary schools (colleges) 
of the day. In these schools the child spent about six years in humanities/ 

* L tommc e$t ne pour penser dc lui-meme. 


learning mostly Latin and some Greek; one or two years in rhetoric/ 
where he learned to write discourses called amplifications (a very suitable 
name, thought D Alembert, since they ordinarily consist of drowning in 
two sheets of verbiage what one could and should say in two lines ) ; and 
two years in philosophy/ which smacked strongly of the content and 
methods of medieval scholasticism. This was the education that he himself 
had had, and in retrospect it seemed execrable. He wanted in the course of 
study more history, more modern languages, and more study of a child s 
native tongue. He thought that the study of English and Italian would be 
particularly useful, perhaps also German and Spanish. And then, knowing 
that his far-sweeping criticisms and suggestions for reform would engender 
against him a great deal of counter-criticism, he concluded by remarking 
that this is what the love for the common weal has inspired me to say on 
education, whether public or private. ... I cannot think without regret 
of the time that I lost in my childhood: I impute this irreparable loss to 
the established custom and not to my masters; and I should like my experi 
ence to be useful to my country. 41 

It was fully characteristic of the Encyclopedists in their general desire 
for reform not to overlook so important a matter as education. But it is 
also likely that in writing this article D Alembert was satisfying his grudge 
against the Jesuits fully as much as gratifying his zeal for the public good. 
D Alembert, a man who thought it bad policy ever to forget a slight, made 
a number of rather spiteful and quite unmistakable allusions, in his fore 
word to Volume III and in the list of errata, to certain persons who had 
been the sources of the Encyclopedic 3 recent woes. In particular, he pointed 
out the plagiarisms in the Dictionnaire de Trevoux, while brazenly and 
impenitently defending his own.* 2 And the proof that he was aiming at the 
Jesuits in his article on College lies in his severe criticism of the dramatic 
productions staged there, which, as everyone knew, were employed by the 
Jesuits as an educational device much more than by anyone else. 43 

D Alembert s article provoked a pamphlet, probably written by a Jesuit 
with a keen eye for an ad hominern argument, for he was at great pains 
to show that Lord Bacon had highly praised Jesuit colleges** Still another 
anonymous pamphlet, this one almost certainly written by a Jesuit, com 
plained of Volume III generally. The pamphleteer disliked in particular 
the choice of subject matter. Articles such as Hat/ Collar/ Cat/ Dog/ 
Candle/ Tost Chaise/ Mushroom/ Hemp/ and Coal he thought too 
long. They have preferred to teach us how to plant cabbages, steep quinces, 
sow hemp, cook lemons and pumpkins, and other bagatelles of the sort; 


but as for the Colosseum, they have said in a dozen lines all that one needs 
to know about it, or, rather, aE that they know about U . . . A wo k ke 
the Encyclopedic . . . should contain only such knowledge as makes true 

Ndererot nor the Journal dc Trtvoux took any part, at least openly 
in Ise bickerings. But the Jesuits in Lyon, the second otjr of France, ook 
up the cudgels. Several times during the Lenten season of 1754 *** P~ ff 
Igainst ^Encyclopedic, and in November of that year they posted foho 
broadsides-there is a copy in the Bibliotheque NaUonale signed by the 
principal orator s own hand - inviting the public to a meetmg m behaj 
o the public schools against the Encyclopedists (Pro Sckoks ^ ,ad- 
versus Encyclopaedias). According to a letter written to Malesherbes about 
this occasion, the orator inveighed for an hour and a quarter -m Latin, 
of course-accusing the Encyclopedic of disloyalty to the monarchy pomt- 
ing out its plagiarisms, and particularly attacking the artic k on College^ 
D^lembert was insulted by a sneering reference to his illegiumate bnth 
allegedly made during the harangue, although this was subsequent^ denied 
and could not be substantiated. D Alembert made as much troub e as he 
could for the orator, Father Tolomas, and the Royal Society of Lyon to 
which the priest belonged, but without obtaining much satisfaction, and 
thus the incident sputtered out inconclusively * 6 

His quarrel with the Jesuits at Lyon was not the only incident occurring 
at about this time in which D Alembert made it a matter of policy to make 
people think twice before they lampooned an Encyclopedist. A budding 
provincial playwright named Palissot caricatured Rousseau in a play pro- 
duced atNancy in 1755. Palissot made his offense even worse in D Alembert s 
eyes by having his play printed and published at Paris. D Alembert leaped 
to Rousseau s defense, and caused as much difficulty for Palissot as he was 
able his principal handicap being that the forgiving Rousseau wanted no 
trouble made at all.* 7 This incident, occurring in 1755-6, made even more con 
spicuous the break between Rousseau and his former friends which came 

three years later. 


Volume IV of the Encyclopedic, published in October 1754, proceeded 
from CONSEIL to DIZ in eleven hundred pages, its dignity somewhat 
impaired by its own admissions that it was something less than perfect. 48 
Thus the list of errata plaintively entreated its contributors to take care 
that their manuscripts be legible, especially in regard to proper names, and 
that punctuation be exact in the places where the sense is necessarily am- 


biguous. This was in addition to a note that had already been published 
in the errata in Volume II: The work of the editors, as editors, consists 
solely in collecting and publishing the work of others together with their 
own; but they have never purported to undertake either recasting articles 
done by others or going back to the sources whence they might have been 
taken, so that the editorial disclaimers, one implicit and one explicit, added 
up to a rather damaging admission of shortcomings. 

Volume IV, of all the volumes that had yet appeared, gave the impression 
of being the most objective and the least controversial. Accordingly, criticisms 
of it were comparatively rare. The Abbe Raynal, writing in his confidential 
news letter, was an exception, but perhaps he was offended (being a his 
torian who had published books on English, Dutch, and general European 
history) at not being asked to be a contributor. 49 That he was not is a fact 
that highlights the Encyclopedias lack of interest in political and military 

A notable omission in this volume was the absence of any article on Con 
stitution, that is to say the papal bull Unigenitus, which had caused so much 
political and religious strife in France since its promulgation in 1713. This 
was a delicate topic indeed, especially as the Parlement of Paris had been 
exiled to Pontoise over this very issue the preceding year, and passions 
were still running high. Drafts of a projected article are still in existence, 
but Malesherbes finally decided that the subject was too hot to handle and 
ordered Diderot not to publish anything concerning it. 50 Included, however, 
were all the usual features and some new ones: the usual abundance of 
articles of the type now grown familiar to us long descriptions by Diderot, 
such as those on Ropemaking (Corderie), and Lace (Dentelle), and Cot 
ton/ this last based on a memorandum furnished by Turgot, soon to be 
come famous as a gifted public administrator. This was the type of article 
complained of by some as being too long, but which Diderot defended by 
saying that there was more to fear from their being too brief, everything 
in handiwork being almost equally essential and equally difficult to de 
scribe. 51 There were numerous articles once more by Boucher d Argis on 
laws and legal and political institutions, as also articles by Forbonnais on 
business, besides contributions by interesting new authors. Dr. Theophile 
de Bordeu, who had recently published some important pioneering research 
on glands and who came to exert a considerable influence upon the thinking 
of Diderot, wrote an article, Crisis,* which was a description and discussion 
of the art of healing. Claude Bourgelat, who later founded the schools of 
veterinary medicine in France, began in Volume IV to contribute articles 


on horse-training and farriery so original and extraordinary that it has been 
said they were the first to give to the veterinary art a scientific direction. An 
other valuable acquisition was Duclos, historiographer of France and per 
manent secretary of the French Academy. But the shining jewel in the 
Encyclopedic diadem was the name of Voltaire, announced as the author 
of articles to appear in Volume V. 

That Voltaire consented to contribute articles, or offered to do so it 
is uncertain which is the fact - constitutes proof by itself of the success and 
prestige that the Encyclopedic had attained. For France s most famous man 
of letters, living at Geneva since he had worn his welcome thin at Potsdam, 
had a shrewd and foxy sense for keeping in the public view, and was un 
likely to contribute to the prestige of an enterprise unless it offered a strong 
probability of enhancing his own. For the remaining twenty-five years of his 
life, until the apotheosis in Paris in 1778, Voltaire continued to live in or 
near Geneva, sometimes at Les Dflices in Genevan territory or at^Ferney 
in French, reluctant to live all the time in the one because playacting was 
forbidden, and poised in the other so that he could move agilely over the 
border if danger threatened. During this long period he managed to keep 
himself the cynosure of Parisian eyes, the dictator in many respects of 
Parisian tastes. This was, in reality, a very great accomplishment. It meant 
that he must miss no opportunity of feeling the pulse of Parisian opinion. 
It meant that to keep in the public eye he must have something to say on 
almost every subject and a piquant rejoinder to almost every pamphleteer. 
People who regret that Voltaire wasted his talents replying to every wretched 
hack who took it into his head to attack him miss the point: these replies 
kept him alive in the public recollection. Living practically in exile, two 
hundred and fifty miles from Paris in space and a fortnight in time, his 
problem was to manage by some feat of intellectual prestidigitation to seem 
to be leading Parisian public opinion while in reality following it. For 
twenty-five years he performed this sort of Indian rope trick. Voltaire, the 
cunning Voltaire, needed all his cunning not to be forgotten, and it is a 
testimony to the real success of the Encyclopedic that he saw self-advantage 
in being associated with it. 

Although Volume IV gives the impression of settling down to a some 
what less controversial tone, it must not be supposed that fire and color 
were lacking. As always, the editors used the columns to flog their enemies, 
as in the anti-Jansenist article by D Alembert on Convulsionnaires, or the 
article on Controversy* in which Diderot ironically and solemnly cites the 


authority of the Dictionnaire de Trevoux? 2 As always, there was the desire 
for economic and social improvement, as in Diderot s wondering whether 
there could not be found in the French dominions a plant with an under- 
bark fiber suitable for weaving, or in the long article on forced labor on the 
public highways (Corvee), in which the author suggested ways for in 
creasing efficiency while reducing the hardships caused the peasants. 53 As 
always, there were the admonitory articles on correct scientific method, 
such as Diderot s on Credulity and Belief (Croire), articles which were 
likely to bemuse their readers concerning the basis for faith in the evidences 
of the Christian religion. As always, there were long and solemn articles 
on subjects dealing with the Old Testament, as, for example, the article 
Deluge, which raised about as many common-sense questions about the 
Flood as the article in Volume I had done about Noah s Ark. And, as 
always, there were Diderot s own contributions, colorful, volatile, impudent, 
sometimes profound. 

Diderot s use of irony and of what Americans call the dead pan is 
well shown in his article on Damnation. Damnation, he wrote, signifies 
eternal punishment in Hell. The dogma of damnation or of eternal punish 
ment is clearly revealed by Scripture. Therefore it is no longer a question of 
seeking to determine by reason whether or not it is possible for a finite 
being to do God an infinite injury; or whether or not the eternalness of 
punishment is not more contrary to His goodness than conformable to His 
justice; or whether, because it has pleased Him to ordain an infinite reward 
for good, He has or has not been able to ordain an infinite punishment for 
evil. In place of becoming entangled in a web of captious reasonings, likely 
to shake a faith not well established, one should submit to the authority of 
the Holy Books and the decisions of the Church, and, trembling, effect 
one s salvation, ceaselessly considering that the enormity of the offense is 
in direct proportion to the dignity of the offended, and in inverse proportion 
to the offender, and [ceaselessly considering] what must be the enormity of 
our disobedience, if that of the first man could be effaced by nothing less 
than the blood of the Son of God. 54 

Intentionally challenging as was this kind of article, deceptively planting 
doubt while saying the unexceptionable, Diderot seems to have felt that 
its apparent conformity needed justification. In this volume, he himself 
wrote that one should not suppose that sages like Socrates, Plato, and 
Cicero, and others, always spoke according to the ideas of the people : 
nevertheless they were sometimes obliged to conform to them in order not 


to be accused of atheism/ 55 Surely for contemporary readers of the Encyclo 
pedic the application of this remark to certain living sages must have been 


Among Diderot s contributions were his customary articles of preponder 
antly literary interest, the articles on word definition and analysis of synonyms, 
the import of which was primarily psychological or belletristic rather than 
Informative. Often Diderot fitted the rhythm of his prose to the mood of 
what he was describing, so that he not only explained his subject but 
represented it, as has been strikingly brought out in regard to the article 
Enjoyment 1 (Jottissanct) ** In Volume IV Diderot wrote an article of 
this sort, sensitively analyzing the various meanings of the word delicious 
and especially describing the deliciousness of sinking into repose. Grimm 
called it one of the most precious things written in French/ and a modern 
critic, who specializes in the study of Diderot and of Baudelaire, speaks of 
it as a completely modern analysis of the consciousness of the fleeting and 
the evanescent. 57 

Two of Diderot s articles that Grimm particularly commended were long 
ones devoted to the philosophical schools of the Cynics and Cyrenaics. 58 
These exercises by Diderot in the history of philosophy were not without 
precedent, for he had written the long article on Aristotelianism in Volume 
I. In Volumes II and III, however, he had tended to delegate these tasks 
to the Abbe Pestre, a shadowy figure who, after the De Prades affair, fades 
out of the Encyclopedic in the unobtrusive way that Alice observed in the 
Cheshire cat. From that point on, Diderot took over this assignment. His 
articles were so highly regarded that Naigeon, thirty-five years later, col 
lected and republished seventy-three of them in a successor of Diderot s 
Encyclopedic, the Encyclopedic methodique, which first appeared in 1781 
and ran to 229 volumes before it desisted in 1832. In practically every case 
the information in these articles by Diderot was freely borrowed from a 
recent history of philosophy written in Latin by a German named Brucker, 
a fact which Diderot did not attempt to conceal. 59 Naigeon says that Diderot 
regretted that the pressure of time necessitated his following Brucker, even 
to the point of adopting his arrangement and organization of subject matter. 60 
But it is still true that Diderot put enough of himself into these articles 
to make them more than a mere transcription, and a French student of the 
Encyclopedic has declared, even after making allowance for Brucker and 
another source named Deslandes, that Diderot is practically the creator of 
the history of philosophy in France. 61 Moreover, his personal additions not 
infrequently have a biographical interest. In the articles on Cynics and 


Cyrenaics, for example, written as they were not later than mid-1754, 
Diderot betrays sentiments that probably betoken a growing antagonism 
to the austere views of his friend Rousseau. 62 

The Encyclopedic was a growing success. What is more, Diderot knew it 
At least it is tempting to infer so from the fact that about this time he de 
manded greater remuneration from his publishers, as we shall see, and also 
from the fact that about this period he refused in an amusingly high-and- 
mighty way a contribution from one of the century s greatest names. The 
Abbe Trublet, who was a sort of literary representative of the famous 
Fontenelle, tells the story: MM. d Alembert and Diderot appearing to 
desire to have something of M. de Fontenelle s for the Encyclopedic, I 
had delivery made to the second [i.e. Diderot] of the fragments on the Greek 
dramatic poets, the only manuscript of M. de Fontenelle that I then had, 
he being still alive [he died a centenarian in 1757]. Some time afterwards I 
asked M. Diderot whether he would use them. He replied to me with 
vivacity that he would take good care not to insert in the Encyclopedic 
a writing in which Aeschylus was treated as being crazy; and it is true that 
M. de Fontenelle said that approximately, although less crudely. C3 It was 
like Diderot to respond emphatically and with vivacity. Thus did its 
editor, in his reverence for the classics, defend Aeschylus at the cost of 
rejecting for the Encyclopedic a contribution from one of the most famous 
men of letters in France. 


Business and Pleasure: A New Contract, 
Mme Geoffrin s Salon, Sophie Volland 


FN LATE 1754, with four volumes of the Encyclopedic 
off the press, Diderot could look back with gratifica 
tion upon a number o arduous, eventful, and productive years. Not only 
had he borne the principal burden of editing a work of formidable size, 
but he had also found time in the years just preceding to write some in 
fluential books. Now he took time off for a visit to Langres, the first he is 
known to have made for twelve years and the last, it turned out, while 
his father was living. Having left his wife and year-old daughter in the 
apartment on the Rue de 1 Estrapade, he spent at least ten days in Langres, 
where, among other things, he lent five hundred livres to a local husband 
man and stood godfather to a Caroillon child, destined one day to be 
brother-in-law to Diderot s own daughter. 1 It is apparent that the Langres 
folk still thought of Diderot as being conscientiously able to accept the duties 
of a Christian godfather. It would be interesting, and more to the point, to 
know why Diderot, too, thought so. 

It is quite evident that Diderot had an enjoyable time at Langres. His 
letter of thanks, a very long one addressed to all his relatives and friends, 
was that of a man writing to people he likes. It was written with a touch 
of robustiousness and vulgarity by no means foreign to the Diderot style, 
but in this instance specially tailored to please the taste of unfastidious 
provincial folk. It is a little as though Diderot thought of himself as writing 
to the people in a painting by Jan Steen. And a succeeding letter shows 
how thoroughly he had renewed old friendships. In it he describes to the 
Caroillon family how, upon his return to Paris, he shamelessly ingratiated 
himself, in their behalf, with a wealthy old Parisian aunt of theirs, and 
goes on exuberantly to speak of his hopes for the future marriage of his 



daughter (aged one and a half!) with a Caroillon son (aged nine), a mar 
riage which, in fact, eventually came to pass. 2 

Diderot has left a vivid picture of the family circle at Langrcs in a 
dialogue entitled Conversation of a Father with his Children, or Con 
cerning the Danger of Putting Oneself above the Law* (Entrctien d un 
fere avec ses enjants, ou du danger dc se mettre au-dessu$ des lots)? The 
discussion gave the author an opportunity to describe the compassionate 
but evenhanded justice of his father, the generous and tender impulses of 
his sister, the harsh and unbending qualities of his abbe brother, and his 
own magnanimous and somewhat quixotic impulses. Although written much 
later, it must surely describe the family group of this very time. Moreover, 
this lively and endearing dialogue probably reports a conversation much 
as it really occurred, for Diderot, while very imaginative and creative 
in matters of imagery and scientific thought, was remarkably uninventive 
in regard to plots and characters. He could observe meticulously, he could 
report with great verve, and once he had begun to take flight, he could 
soar. But it has been remarked that he frequently needed the memory of 
a real event or a real person to inspire him, so that it very often turns out 
that the stories he tells actually happened. 4 In this dialogue he mentions 
some of the persons by their real names, such as the family notary Jean- 
Louis Dubois, not bothering to conceal their identity even when he knew 
that the piece was going to be published. Therefore the presumption is all 
the greater that this conversation, which concerned difficult cases of conscience 
Diderot loved to discuss difficult cases of conscience really took place. 

While at Langres Diderot consulted his relatives concerning his relations 
with the publishers of the Encyclopedic, even to the point of receiving 
elaborate legal advice from the notary Dubois. Thus he writes to his family, 
Scarcely had I returned to Paris when my publishers were informed of it 
and a day appointed for discussing our interests. We all put so much heat 
and so little reason into our first interview that I thought we would not 
be seeing one another again. There wasn t a single one of the articles of 
the contract drawn up by M. Dubois that was not attacked/ In this letter 
Diderot wrote as if he was determined to retire to Langres if he did not 
secure what he demanded. 5 But after an elaborate negotiation, involving 
many intermediaries and numerous compromises, a new contract was signed 
on 20 December 1754. 

The preamble of this document recounts that Diderot had pointed out 
that the amount of work in the Encyclopedic had increased since the previous 
contract had been signed. Therefore the publishers agreed that beginning 


with the fifth volume they would pay Diderot 2500 livres a volume, 1500 
livres payable when the first copy for a volume, the other 1000 when the 
last, was handed in. Moreover, within three months of the publication of 
the last volume of letterpress, Diderot was to receive a lump sum of 20,000 
livres. All books hitherto supplied him as sources or for reference in editing 
the Encyclopedic were henceforth to be regarded as his property these books 
were the backbone of the library he later sold to Catherine II of Russia 
and the publishers put in writing that the said M. Diderot will be in 
the future, as he has been in the past, editor of all the parts of the Ency- 
clopSdie! e It might be remarked that no previous document had so pre 
cisely defined Diderot s position. 

About this time, probably because the new contract made it financially 
feasible, the Diderot family moved to more spacious quarters. For the 
remaining thirty years of Diderot s life the family lived on the fourth floor 
(fifth, American style) of a building in which Diderot also rented space 
for his study on the floor above, directly beneath the roof. The building 
stood on the corner of the Rue Taranne, which no longer exists, and the 
Rue Saint-Benott, which still does. Were the building in which Diderot 
lived still standing it was pulled down in 1866 it would be on the 
Boulevard Saint-Germain directly across the street from the Cafe de Flore, 
in the heart of the domain of the existentialists. A fine statue of Diderot, 
done in bronze by Jean Gautherin in 1885, stands near the site. 7 

A phrase in his thank-you letter to Langres suggests that Diderot had 
come to distrust D Alembert. I don t know how it was, he wrote, that 
during this interval impatience did not seize me and I did not send them 
packing to all the devils, them, the Encyclopedic, their papers, and their 
contract; a little more confidence in the probity of my colleague, and that 
would have done it. 8 This must mean that Diderot suspected D Alembert 
of being willing to supplant him as principal editor. The lack of cordiality 
between the two men ultimately became marked enough to be noted by 
Marmontel. The house of Baron d Holbach and, since some little time, 
that of Helvetius, were the rendezvous for this society, composed partly of 
the cream of Mme Geoffrin s guests and partly of some individuals whom 
Mme Geoffrin deemed too bold and too venturesome to be admitted to 
her dinners. . . . 

1 have never known very well why D Alembert held himself aloof from 
the society of which I speak. He and Diderot, associates in exertion and in 
glory in the enterprise of the Encyclopedic, had at first been cordially united, 
but they were no longer. They spoke of each other with much esteem, but 


they were not intimate and they scarcely saw each other any more. I never 
dared to ask them the reason for it. 9 

The year 1754 was a particularly auspicious one for D Alembert, for in 
the course of it he received the greatest honor his writings could earn in 
France, election to the French Academy. This institution, which had been 
founded by the great Cardinal Richelieu, existed under the direct patronage 
of the king of France, and inclusion among its forty members conferred 
such prestige that even princes of the royal blood, such as the Comte de 
Clermont in this very year, sought election to it. One of the Academy s most 
endearing and most pathetic conceits has ever been that its membership 
confers immortality. In the buildings of the Institut de France, on the 
eighteenth-century doors to the charming room in which the Academy does 
its work, there is wrought in intricate and garlanded design the phrase 
A I lmmortalite. It is scarcely necessary to remark, however, that laurel 
leaves also, like the men who wore them, can turn to dust. 

D Alembert fully deserved his election. He was more than a man of 
science, France s greatest living mathematician; he was also a talented and 
influential man of letters, as witness his Preliminary Discourse to the 
Encyclopedic, as well as other writings collected and published in 1753 
under the tide of Melanges de litterature, d histoire, et de philosophic. Yet 
his election could not help but be widely interpreted as more than simply 
a personal recognition. It was also a victory for the Encyclopedic and for 
the new philosophy. The prestige of the new outlook increased in step 
with his, and the fact that he had gained admittance to the citadel of 
French letters not unnaturally caused the philosophes to hope, and their 
enemies to dread, that this was to be only their first entry into the Academy. 
D Alembert s election increased if anything was still able to increase 
the self-confidence and self-esteem of a group that was rapidly becoming 
a kind of party or sect. 

This tendency of the philosophes to coalesce into a coterie became a sub 
ject of frequent and exasperated remark during the 1750*$. Freron in his 
Annee Litteraire rarely let the opportunity pass to complain of it, and even 
the Abbe Raynal, who was more a friend than an enemy of the philosophes, 
remarked in his private news letter during 1754 upon the harsh tone and 
bad temper that some men of letters of today mistake for philosophy. . . . 
If the tone of criticism is abandoned [he went on], it is for the purpose of 
elevating to the third heaven the authors of the Encyclopedic and the author 
of the Histoire naturelle [Buffon]; aside from them there is nothing praise 
worthy any more. They it is who have taught us to think and to write, 


who have re-established good taste and philosophy, and who preserve them. 
Nevertheless, one asks all the time, what have they done? These gentlemen, 
no doubt esteemworthy by virtue of their knowledge, wit, and manners, 
degrade their philosophy by a domineering and lawmaking tone, by an 
affectation of arrogating to themselves a despotism over literary matters 
and by their propensity to burn incense to one another everywhere and 

endlessly. . . . 10 1117 

This flattering sense of being one of an elite was nurtured by the salon, 
a social institution of peculiar efficacy in generating a spirit of group co- 
hesiveness. Given the centralization of French social and intellectual Me, 
at least since the beginning of the seventeenth century, the Parisian salon 
has always been, like a gambling house, a place in which fortunes are made 
or lost. Often a salon has been of incalculable assistance in launching an 
author or, inversely, in wrecking another; and in no epoch was this more 
evidently true than in the eighteenth century. For that was a sociable age, 
and the ideas that were transforming society and predisposing it for change 
were ideas freely canvassed and exchanged in the agreeable leisure of these 
social hours. The connotation of the word salon, used in this special sense, 
was of an open house the purpose of which was intellectual discussion. 
Usually the word implied, too, that the hospitality was extended by a lady, 
acting as ringmistress, or, as Henry James put it, directing ^through a 
smiling land, between suggestive shores, a sinuous stream of talk. Although 
of course D Holbach s was a salon, too, the more typical eighteenth-century 
salons were those of Mme du Deffand, Mme Geoffrin, Mile de Lespinasse, 
and Mme Necker. 

It took a great deal of skill and tact to run a salon successfully, to gain the 
respect of temperamental authors and intellectuals, to make them want to 
come again, to be able to steer a conversation without being obvious, to 
govern discussions so adroitly that they became neither anarchical nor 
contentious, to draw out the timid and circumvent the bores. No one was 
more proficient, more gentle but firm, in the exercise of these skills than 
Mme Geoffrin, so that her house came to be nicknamed, in deference both 
to her prestige and to her authority, The Kingdom of Rue Saint-HonoreV " 
It is still standing, hard by the Place Vendome and the Place de la Concorde, 
this house which became a rallying point for philosophy, especially by 
virtue of the famous dinners she gave for men of letters every Wednesday. 
Artists were fed on Mondays. 
This is not to say that discussions at Mme Geoffrin s were ever so bold 


and fearless as they were at D Holbach s. Mme Geoffrin was rather timorous 
and very cautious, so that, as Marmontel remarked, she held Diderot, the 
most original and prolific thinker of them all, at arm s length. At Mme 
Geoffrin s, wrote Marmontel, the philosophes were led about and held in 
leading strings/ 12 But this very prudence and timidity worked to the profit of 
the Encyclopedists. At the moment when her salon was being opened, wrote 
a distinguished editor of the Revue des Deux Mondcs, those who were 
going to form the army of the Encyclopedists were still isolated, strangers, 
or hostile to one another, and little known or litde appreciated by the public. 
They grouped themselves at Mme Geoffrin s: at her house they found a 
center of reunion where they learned to get together, to support one another, 
and to make common cause. There they submitted to discipline. A lover of 
propriety and moderation, the mistress of the house prevented them from 
colliding too violently with public opinion or governmental power, and she 
saved them from the danger of ruining themselves by their own im 
patience. 13 This is well said. It may be supplemented by a police report of 
1751 about Mme Geoffrin, giving some of the down-to-earth aspects of 
operating a salon: 

There assembles every afternoon at this lady s house a circle of wits, among 
whom are especially M. de Fontenelle and Helvetius, Farmer General, who are 
her friends. 

She often provides meals. 

Also she sells the rarest new books; that is to say, the authors send her a dozen 
copies and she takes pleasure in making her friends buy them. 1 * 

The functioning of a literary circle resembling that of Mme Geoffrin 
is reflected in the Memoirs of M. de Voltaire by Oliver Goldsmith, who 
claimed to have been an eyewitness of a spirited dispute involving Fontenelle, 
Diderot, and Voltaire. This must have occurred, if anything like it really 
did take place, during 1755, when Goldsmith was in France. It would be 
pleasant to think that Diderot and Goldsmith were acquainted, but the 
latter s story is demonstrably inaccurate in part (for Voltaire was not in 
Paris in 1755 and never met Diderot until 1778), leaving one to fear that 
perhaps it is false in toto.^ 

For Diderot the importance of Mme Geoffrin s salon was chiefly indirect. 
It existed. It was valuable. It provided a powerful support for the new 
outlook represented by the Encyclopedic. But it functioned almost exclusively 
without his presence, whether he voluntarily abstained because he disliked 


the constraint that Mme Geoffrin put upon her guests, or whether he was 
made to feel that she liked him better absent. Certainly there is no evidence 
of antagonism between them, and she was exceedingly generous with him 
in respect to money. Yet she distrusted him, for both his manners and ideas 
made him difficult to manage. As Marmontel remarked, Diderot was not 
admitted to her dinners. Diderot did not go to Mme Geoffrm s, wrote 
another of his contemporaries, She feared his impetuosity, the rashness of 
his opinions, supported, when he was aroused, by a fiery and stirring elo 
quence. 16 And she herself, writing in 1774 to her protege, the King of 
Poland, spoke of Diderot in cool and measured terms. He is an upright 
man/ she wrote, but he is wrongheaded. And he is so wrongly constituted 
that he neither sees nor hears anything as it really is. He is always like a 
man in a dream, and who believes everything that he has dreamed/ 17 

At about this period Diderot made the acquaintance of a man whose recol 
lection of their meeting imparts precious information as to what kind of 
first impression Diderot was likely to make. The new acquaintance was 
Charles de Brosses, a magistrate from Dijon, who had asked his former 
schoolmate, Buffon, for an introduction to Diderot, that extraordinary 
metaphysical head. He is an agreeable fellow,* reported De Brosses, very 
charming, very likable, a great philosopher, a great arguer, but dealing in 
perpetual digressions. He made a good twenty-five of them in my room 
yesterday, from nine o clock to one. 1S 

De Brosses was a man of broad intellectual attainments, and he and 
Diderot quickly became very friendly. Diderot almost importunately solicited 
from him for publication in the Encyclopedic the manuscript of a long 
article on Etymology. 19 As De Brosses later described the episode, Diderot 
kept the manuscript for two or three years in spite of De Brosses s reiterated 
requests that it be returned for revision. The article that finally came out on 
this subject in the Encyclopedic, however, was written not by De Brosses 
but by Turgot, who evidently had used the De Brosses manuscript as a 
starting point. De Brosses was rather startled at this outcome, although he 
did not question that Turgot had acted in the best of faith. He was inclined, 
however, to accuse Diderot of negligence and thoughtlessness. 20 Here we 
have a glimpse of the careless and nonchalant side of Diderot, whose pos 
session of such disconcerting although sometimes endearing qualities made 
dealing with him an experience not infrequently frustrating. 

At the time that Diderot made the acquaintance of De Brosses, the 
Academy of Dijon had just announced a prize contest on the subject, "What 


is the origin of inequality among men, and is it authorized by natural law?* 
Since De Brosses was a member of the Academy of Dijon, Diderot s con 
versations with him naturally came around to this topic. The subject ap 
pealed strongly to Diderot, and yet he did not compete for the prize. De 
Brosses reveals why: Diderot talks to me a great deal about the subject 
of this prize. He finds it very fine but impossible to deal with under a 
monarchy. He is a daring philosopher, with a vengeance/ 21 

Diderot s friend Jean-Jacques felt no such restrictions. He submitted an 
essay which, though it did not win the prize, nevertheless became one 
of his most famous works. In view of the foregoing evidence of Diderot s 
preoccupation with the subject, it is interesting to speculate upon just how 
much he may have influenced this essay. Rousseau declared in his Con 
fessions that the Discourse on Inequality was the work that was more to 
Diderot s taste than any other of my writings, and for which his counsel 
was the most useful to me/ Somewhat later Rousseau even identified a 
passage in the Discourse on Inequality that Diderot had written, but by this 
time Jean-Jacques was no longer of the persuasion that Diderot had been 
really helpful. It is certain, he wrote, that M. Diderot always abused my 
confidence and my compliance in order to impart to my writings a harsh 
tone and a gloomy air that they no longer had as soon as he ceased to direct 
me and I was left completely to myself. 22 Recent scholarship is inclined 
to the view that there may indeed have been in Diderot a vein of primitivism 
fiercer and more stubborn than in Rousseau himself. 23 Building upon Rous 
seau s own admission, it is generally supposed that Diderot s share in the 
ideas incorporated into Rousseau s Discourse on the Origin of Inequality 
is considerable. 24 

As the Encyclopedic went into the letter , one of Diderot s contributions 
was an article intended to be published under the title of Encaustic/ 25 For 
some reason he decided to publish it separately, and accordingly there ap 
peared anonymously in a very small edition in 1755, L Histoire et le secret 
de la peinture en cire ( The History and Secret of Painting in Wax ). 26 The 
article Encaustic as it appeared in Volume V was done by another hand. 27 

This rather recondite subject was nevertheless topical because of the 
considerable discussion in Paris just at this time as to precisely what had 
been the method used by the ancients for painting in wax and for fixing 
the colors by the application of heat. The technique is very difficult, but 
gives special effects and is of extraordinary durability. It has been practiced 
today in this country with remarkable technical and aesthetic success by 


Karl Zerbe of the Boston Museum School of Fine Arts. One of Diderot s 
acquaintances, an artist named Bachelier, thought he had rediscovered the 
ancient technique in 1749, but had done nothing about publicizing it. In 
1753 the Comte de Caylus published the first of a series of papers in which 
he claimed to have deciphered the cryptic passages in Pliny the Elder re 
garding this ancient technique and therefore to be the first to recover the 
long-lost method. 28 

Caylus, however, made a mystery of the actual technique employed in 
duplicating the ancient method. This sort of obscurantism in matters re 
lating to the sciences or the arts, indeed any sort of obscurantism, always 
infuriated Diderot, and in consequence his pamphlet was as much aimed 
against Caylus as the Letter on the Blind had been a rebuke of Reaumur. 
The first words of the new work were: Nothing is more contrary to the 
progress of knowledge than mystery/ 29 Then he attempted to prove that 
neither Bachelier, in 1749, nor Caylus had really come upon the true ancient 
encaustic, but that Bachelier had since discovered it in further experiments. 
Since Bachelier was trying to keep the discovery secret, Diderot nonchalantly 
put himself into the invidious position of revealing a secret that was not 
his property. 1 do not doubt, he wrote, but what M. Bachelier bears me 
a grudge for publishing his secret. ... But I have my own character and 
my own fashion of thinking, which I find satisfactory and from which I 
shall not withdraw for the sake of M. Bachelier. What I know of his methods 
of painting I owe solely to the pains I took to teach myself regarding it. I 
promised no one to keep the secret. 30 Diderot s attitude was consistent 
with his freely bestowing upon the public his own ideas for the improve 
ment of barrel organs. Nevertheless, with a characteristic impetuosity and 
lack of second thought and with even a certain officiousness, he deeply .dis 
obliged both Caylus and Bachelier by what he claimed to be his zeal for the 
public good. 

The Comte was a wealthy amateur and expert who was a sort of dictator, 
apparently a crotchety and crabbed one, in the world of art. 31 One can well 
imagine what he thought of Diderot. When an Italian correspondent in 
nocently happened to inquire in 1761 how Diderot was, Caylus replied, 1 
know Diderot very little because I do not esteem him, but I believe he is 
well. There are certain bougres who don t die, while, to the misfortune 
of letters in Europe, honest folk like Melot [Anicet Melot (1697-1759), a 
French antiquarian] die in their prime. 32 And what Diderot thought about 
Caylus was expressed in an epitaph Diderot wrote in 1765. Caylus had 


expressed the desire to be buried in an Etruscan urn that was in his garden, 
and Diderot wrote, in a very well-turned couplet: 33 

Ci-git un antiquairc acariatrc et brusque; 

Ah! qu il est bicn loge dans cette cruche etrusque! * 

The pamphlet on Encaustic is characteristic of Diderot s point o view 
and redolent of his personality. Time and again he emphasizes the im 
portance of disseminating knowledge. 34 If it happens/ he writes, that 
an invention favorable to the progress of the arts and sciences comes to my 
knowledge, I burn to divulge it: that is my mania. Born communicative as 
much as it is possible to be, it is too bad that I was not born more inventive: 
I would have told my ideas to the first comer. Had I but one secret for all 
my stock in trade, it seems to me that if the general good should require 
the publication of it, I should prefer to die honestly on a street corner, my 
back against a post, than to let my fellow men suffer. . . . 35 And he wishes 
that there might be established a royal academy of the mechanical arts. 36 
Moreover, Diderot s interest in the applied, the factual, and the practical 
(as well as in the generalized and the purely theoretical) is abundantly 
shown in this booklet. Here is a man who knows as much as any man in 
his day about the chemistry of paints. Here is an author fully aware of the 
technical procedures of artists, as well as of their problems of composition 
and aesthetic intent. The History and Secret of Painting in Wax: reveals 
also the classicist, able to translate and analyze Pliny s elliptic and obscure 
remarks. Finally, in this pamphlet which Grimm described as written 
with much fire, a rapid pace, and much gaiety/ and which Freron declared 
to be diffuse and overburdened with notes, some of which try to be scien 
tific and the others amusing* we find the subjective and the personal start 
ing out at one, especially in the notes. 37 There s a sentence/ Diderot comments 
concerning a paragraph composed of one single sentence of eighteen lines, 
Very long and tortuous, which is going to be found displeasing. Were it 
the only one, I would correct it. 88 At another place he notes that C A11 that 
follows now seems to me to be out of place; but I have not the courage to 
delete it. J Then in the next note, If I continue in this vein, I shall not finish 
in a hundred pages what could be said in ten, and I shall be reproached for 
having been obscure and diffuse, two faults that usually go together. 3 

* Here lies a crabbed and brusque antiquarian. 
Oh, how appropriately lodged is he in this Etruscan jug! 


And what could be more personal and more revelatory of Diderot s sensitive 
ness than the following? 

. . . we take as great pains to destroy [our masterpieces in painting 
and sculpture] as they [the Ancients] did to preserve theirs. They had a 
varnish that they applied to their pictures, their bronzes, and their marbles 
.... Regularly every year we rub the skin off ours with sponges full of a 
hard and gritty fluid. ... On the days of this cruel operation I flee from 
the Tuileries as one flees from a public place on a day of execution. 40 

The controversy over encaustic painting created some stir and inspired 
a pamphlet ridiculing Diderot s. Its translated title is The New An of 
Painting in Cheese, Invented for Carrying Out the Laudable Project of 
Gradually Finding Ways of Painting Inferior to Those Now in Existence** 
This effusion was by an anonymous author whom Freron found diverting 
and Grimm thought to be in the worst taste since Attila, King of the 
Huns. 42 Irony upon so lordly a scale apparently discouraged other cham 
pions from entering the contest. It was all very well for Grimm to grumble, 
but he and his brothers of kindred spirit did not choose to reply. 

It was about this time that Diderot again fell in love, suddenly and 
violently and enduringly. Little is known of the lady, but evidently she 
possessed a character very different from and much finer than that of Mme 
de Puisieux. None of Sophie Volland s letters to Diderot is extant, so that 
the impression we have of her is very like overhearing one end of a pro 
tracted telephone conversation. Incomplete and distorted as this way of 
knowing her personality inevitably is, it is quite apparent that she was 
modest where Mme de Puisieux was conceited, and self-effacing where 
Mme de Puisieux was self-assertive. Certainly Diderot found in Sophie 
Volland the qualities necessary for a lasting attachment, an attachment 
attenuated perhaps, but never broken off in bitterness enduring the rest 
of their lives. Sophie Volland died five months before Diderot, and in her 
will she left him the keepsakes of a long devotion. 1 give and bequeath to 
M. Diderot seven little volumes of Montaigne s Essays bound in red morocco, 
together with a ring that I call my Pauline. 5 43 

Sophie was a special name. Not the Louise-Henriette of her baptism, 
but the name given to her by Diderot himself in allusion, by means of the 
French form of the Greek word, to the wisdom which seemed to him the 
quintessence of her qualities. 44 It is as Sophie Volland that she has become 
posthumously famous, the inspirer and recipient of letters unexcelled in their 
revelation both of a particularly interesting social milieu and of an in 
finitely rich, complex, and humane personality. Grudge not the elderly 


spinster her existence, then/ wrote Carlyle in his essay on Diderot. Say 
not she lived in vain. 

Sophie Volland came from a family, perhaps a wealthy one, of the middle 
class. Her father, Jean-Robert Volland, who died before the lovers met, had 
been an important functionary in the administration of the government 
monopoly of salt, and was closely associated, both in business and by mar 
riage, with the class of financiers and tax farmers whose enormous incomes 
tended to make them the freest spenders of the ancien regime. The Volland 
family was not dedicated to this gospel of conspicuous waste, but the father 
had bought an estate and built a country house at Isle-sur-Marne, near the 
small city of Vitry-le-Franjois to which Sophie s mother spirited her 
away for half of each year in order to separate her from Diderot and it 
is also evident that the family lived comfortably in their town house on 
the Rue des Vieux-Augustins. This was in a quarter now much run down 
but at that time conservatively fashionable, close by the Place des Victoires 
and the grandiose and imposing church of Sainte-Eustache. 45 There is some 
indication in Diderot s letters that the family when he knew it was less 
prosperous than it had been. 

Sophie had two married sisters, and it is remarkable, considering her 
family s affluence, that she was not married too. Perhaps, as one biographer 
of Diderot has surmised, some obscure but unforgotten scandal had impaired 
her matrimonial chances. 46 When Diderot met her, probably in 1755, per 
haps in 1756, she was about forty years of age, three years younger than 
Diderot, having been born on 27 November iji6. 47 What little is known of 
her mainly concerns the state of her health, which evidently was exceedingly 
precarious, so much so that Diderot was constantly fussing over her. Very 
warm days are succeeded by very cool evenings, he wrote her. Watch 
your health. Don t expose yourself to the evening damp. You know what a 
weak little cat s chest you have and what terrible colds you are subject to. 
Two weeks later he wrote, Adieu, my dear. I kiss your forehead, your eyes, 
your mouth, and your dry little hand, which pleases me quite as much as 
a plump one. 48 Biographers, having so little to go on, make much of the 
dry little hand (rnenotte). And they are inclined to speak of Sophie s 
spectacles in the spirit of Dorothy Parker s remark about girls who wear 
glasses. It is from my workshop at Le Breton s that I have been writing 
to you for the past two hours this long, boring letter that you will have a 
good deal of trouble in deciphering. Just omit, pass over, whatever makes 
you rub your glasses on your sleeve, Diderot wrote upon one occasion. 
And upon another, imagining them gathered together at the country house: 


1 hear you all chattering, I see you all in your favorite attitudes, I would 
paint you if I had the time. My dear one would be standing erect behind 
her mother s armchair, facing her sister, and with her spectacles on her 

nose. 4 * 

Had more of Diderot s letters to Sophie Volland remained in existence, 
we would not now be so desperately deficient in information regarding her. 
They are known to have numbered more than five hundred and fifty, but 
Mile Volland herself destroyed all but one hundred and eighty-seven. 50 More 
over, the first one hundred and thirty-four, which might very well have been 
the most interesting of all, have disappeared, and the earliest one we can 
consult is dated May 1759. We are thus reduced to approximations when 
attempting to fix the date when the acquaintance began. Mme de Vandeul 
asserts that her father developed this passion in 1757, when Mme Diderot 
and little Angelique were on a visit to Langres. 51 But Diderot s own letters 
suggest 1755 as the date of meeting. In 1767 he writes somewhat vaguely 
in terms of ten to twelve years, 52 though a year later we find him still 
talking of a dozen years. 53 There is the same indefiniteness in this passage 
from a letter of 1765, regarding a carriage trip on the morrow: 1 shall have 
the pleasure of passing the whole day with her whom I love (which is not 
surprising, for who would not love her?) but whom I love, after eight or 
nine years, with the same passion with which she inspired me on the 
first day that I saw her. We were alone that day, both of us leaning on the 
little green table. I remember what I said to you, what you replied to me. 
Oh, the happy time it was, the time of that green table! 54 Earlier references 
are more precise. One of September 1760 remarks that it will soon be five 
years since they met; and in October of 1759 he writes, It was four years 
ago that you appeared beautiful in my eyes. Today I find you more beautiful 
than ever. This is the magic of constancy, the most difficult and the rarest 
of our virtues. 55 

A good deal of ink has been spilled, perhaps rather needlessly, in speculation 
as to whether Diderot and Sophie Volland were really lovers or just good 
friends. Were Diderot s affections platonic ? This is certainly a problem of 
appropriate biographical interest, but one concerning which a non-French 
biographer might well defer to French expertise. It may be reported, there 
fore, that persons deserving to be regarded as connoisseurs in such matters, 
as, for example, a member of the Academic Goncourt or, for another, the 
author of a book entitled La Vie amoureuse de Diderot, have weightily 
considered the evidence. The majority conclude as most people would 


have assumed from the start that Sophie allowed Diderot what is delicately 
termed the ultimate liberties. 5 56 

Much of what is known about Diderot, the most revealing and the most 
precious information, comes from his correspondence with Sophie Volland. 
It is posterity s loss that, in contrast, so little is known of Sophie herself. 
Was the quality of her mind what Diderot thought it to be, or did he mis 
take the echoing of his own ideas as the evidence of a powerful intelligence 
in her? It would not have been the first or last time that Diderot admired 
himself by seeing in a person or a book something that was not there but 
was simply a projection of his own personality. Besides, Diderot was given 
to some exaggeration in these matters, as when he wrote in his Essay on 
Women, When one writes of women, one must dip one s pen in the 
rainbow and dry the line with the dust of butterflies wings. 5T A reader of 
the letters may easily sentimentalize with Diderot about Sophie Volland 
and perhaps invest her with a character and characteristics that she is not 
positively known to have possessed. But at the very least it can be said 
with certainty that Diderot s second mistress was better than the first. And 
it can also be said, in view of the contents of these letters, that she can 
scarcely be thought a prude. 


Changing the General Way of Thinking 

D 1 

DIDEROT was far from well during the closing 
months of 1755. In late September he alluded 
to his illness in a letter to Caroillon at Langres: I have been and still am 
pretty badly off in my own affairs. I have had my whole chest affected. A 
dry cough. Terrible sweats, difficulty in speaking and breathing. But things 
are going much better, at the price of a drastic remedy: bread, water, and 
milk for my whole diet. Milk in the morning, milk at noon, milk at "tea- 
time," milk at supper. That s a lot of milk/ 1 In circumstances so adverse 
and for most Frenchmen (save perhaps M. Mendes-France), to have to 
cope with that much milk is real adversity Diderot continued his task of 
editing the Encyclopedic and writing articles for it. In particular, he com 
posed his article Encyclopedia for Volume V during this difficult time. 
Rousseau mentioned the article as being the admiration of all Paris/ and 
then went on to say, what will increase your astonishment when you read 
it is the fact that he wrote it while ill. 2 

Despite this sickness, Volume V was delivered to subscribers during the 
first days of November. 3 Like its sisters, it was a portly folio volume, a thou 
sand pages and more, and carried the alphabet to ESY. Its title page took 
cognizance of D Alembert s new honors, mentioning that he was a member 
of the French Academy, the Royal Academy of Belles-Lettres of Sweden, 
and the Institute of Bologna. As usual, new contributors were welcomed to 
the fold, especially Voltaire, whose articles on Elegance, Eloquence, and 
Esprit were not only elegant but also concise, a virtue not always char 
acterizing the Encyclopedias contents. 

Once again a lengthy memoir by D Alembert formed the introduction. 
This one concerned Montesquieu, who had died in February 1755 - Diderot, 
incidentally, happening to be the only man of letters present at the funeral. 4 
Montesquieu had never engaged very deeply in the cause of the Encyclopedic, 



but with the French proclivity for making political capital out of funerals, 
the editors appropriated him. Their excuse was that he was a contributor, 
having written the article on Taste (Gout), a rather mediocre fragment 
as it turned out. Posterity is accustomed to regard the author of UEsprit 
des lots with a good deal of veneration, as did, for example, the authors of 
the Federalist Papers, but in his own lifetime and in his own country con 
servatives looked upon Montesquieu with great disapprobation because he 
seemed to be too fond of talking about the nature of liberty and too pointed 
in implying that France had very little of it. Moreover, his positive and 
factual rather than theological approach to the study of history and politics 
offended many. To reactionaries Montesquieu seemed radical, and it was 
characteristic of the editors of die Encyclopedic to desire to make him their 
own. This they did not only in their introductory memoir but also in the 
course of an article by Diderot on Eclecticism, written like many others of 
his with a sudden flashing swoop from the objective to the personal which 
seems so out of place in a work of reference but which is probably one of the 
major causes of this one s success. Having commented morosely upon 
society s neglect and abuse of genius, he remarked, I wrote these reflections 
on ii February 1755, upon returning from the funeral of one of our greatest 
men, overcome by the loss that the nation and the world of letters had sus 
tained in his person, and profoundly shocked by the persecutions that he 
had undergone. 5 

One of the principal articles in Volume V was written by Diderot on 
Natural Right (Droit naturel). This was a subject in the vein of the great 
natural lawyers of the preceding century, men like Grotius and Pufendorf, 
so that a highly competent political philosopher has been able to say with 
some justification of Diderot s article that it was a rhetorical flourish with 
conventional ideas/ 6 Still, this was a topic difficult to discuss with frankness 
in the France of the eighteenth century. Diderot did discuss it. His article, 
being in the tradition of the natural law school, contributed to keeping 
concepts current that later provided the inspiration for documents like the 
Declaration of Independence and the Declaration of the Rights of Man and 
of the Citizen. Diderot wrote of man s dignity and in 1755 of his inalien 
able rights, T and frequently referred to the general will/ This phrase has 
become so deeply associated with Jean-Jacques Rousseau and his idea of the 
social contract that Montesquieu s earlier use of the term in UEsprit des lots 
seems to have become generally forgotten. 8 In Volume V of the Encyclopedic 
both Diderot, in his article on Droit naturel, and Rousseau, in his on 
Economy/ used the term with some of the identical overtones of meaning 


that are found in the Social Contract seven years later. 9 Thus Diderot wrote 
that Individual wills are under suspicion: they might be good or bad, but 
the general will is always good. It has never deceived, it never will . . . 
the general will never errs/ 10 It is therefore possible that one of the two 
borrowed the term from the other, but, if so, very unclear who from whom. 11 
At all events, when one begins to use the phrase, the general will, the 
concept of popular sovereignty commences to stir. As De Jaucourt had the 
courage to write, and Diderot to publish, in the article on Government/ 
all legitimate sovereign power must emanate from the free consent of the 
people.* 12 

Articles like these were prophetic. And it is worthy of notice that Volume 
V dared to begin publishing again the liberal political articles for which 
Diderot had been so severely criticized when he wrote and published the 
essay on Authority in Volume I. His article on Natural Right, Rousseau s 
on Economy, and De Jaucourt s on Natural Equality (Egalite naturelle) 
expound ideas that already have the smell of 1776 and 1789. Nor did the 
significance of their publication in the Encyclopedic escape the observation 
of contemporaries. If one is ever tempted to suppose that the political views 
expressed in the Encyclopedic were so hesitant and timid as to be innocuous, 
let him recall the words of a British reviewer writing in 1768, words wherein 
a generous-minded liberalism may be seen contending with an English 
jealousy of French progress: We must observe likewise, to the honour of 
the authors who have had the conduct of the Encyclopedic, that the same 
manly freedom of sentiment which is observable in the philosophical and 
other departments of this work, is eminently conspicuous in the political. 
In short, whoever takes the trouble of combining the several political articles, 
will find that they form a noble system of civil liberty; and however, as 
Englishmen, we may have no reason to rejoice at the prospect of a gradual 
establishment of such a system among our rivals, yet as friends to the rights 
of mankind, we are delighted to see such a generous system every where 
expanding its influence. 13 

As for the economic philosophy of the Encyclopedic, it is nowhere better 
depicted than in the long article on Thrift (Epargne) contributed by an 
obscure boarding school director named Faiguet. Reminiscent of, say, Ben 
jamin Franklin, it was an extraordinary piece to appear in 1755 in the midst 
of a monarchical and aristocratic society. For its values were middle-class 
values, very far indeed from those of the nobility. There is something sym 
bolic in M. Faiguet s personal insignificance. He is faceless, which makes 
him the better representative of a class, the class that made the French 


Revolution. This was the class that, like M. Faiguet, regarded thrift as a 
cardinal virtue and, like M. Faiguet too, wanted the medieval guild restric 
tions on production abolished; desired the abolition of apprenticeships and 
journeymen s associations; wanted the abolition of Colbertism by removing 
the obstacles on every hand regarding the transport and sale of merchandise 
and foodstuffs ; and further desired the suppression of three-fourths of our 
religious holidays. M. Faiguet had a keen eye for the labor supply: he 
wanted the state to limit the number of persons admitted to religious orders. 
He thought that thrift would be encouraged by placing much more severe 
limitations on drinking places: The cabarets, being always open, disorder 
our workers so thoroughly that one cannot ordinarily count upon them 
nor see the end of a job once commenced/ He favored the institution of 
state-owned pawn shops which could also serve as banks of deposit. By 
this means there would circulate an infinity of sums great and small that 
remain today in inactivity. M. Faiguet was much opposed to luxury, the 
taste for which he imputed to the mistaken education of the day. Nothing 
is more to be recommended to young folk than this virtuous habit [of 
thrift], which would become for them a preservative against vice. . . . 
Prizes in eloquence and poetry have been founded in a thousand places. Who 
will found among us prizes for thrift and frugality?* 14 M. Faiguet deserves 
immortality: he is the disembodied voice of an upthrusting bourgeoisie. 

Among the articles descriptive of manufacturing or artistic processes that 
Diderot wrote for Volume V were those on distillation of brandy (Eau-de- 
vie) and on Enamel (Email) . In the latter he introduced the personal note 
by mentioning a certain artist and saying, I do myself the honor of being 
a friend of the last named/ 15 D Alembert, too, permitted himself the 
luxury of personal remarks now and again in this volume, as when he 
praised Diderot s Thoughts on the Interpretation of Nature or launched 
forth in castigation of the clandestine Jansenist newspaper, Les Nouvelles 
Ecclesiastiques. The anonymous author of this work, wrote D Alembert, 
. . . could probably name himself without being better known. 16 Also in 
Volume V, to take some samples, were an interesting article on Copyright 
(Droit de copie), contributed by David, one of the publishers of the Ency 
clopedic, and an article on Duels written by Boucher d Argis. Of very special 
interest to economists is the article on how pins are made (Epingle), con 
tributed by a young friend of Diderot and Rousseau named Deleyre. Follow 
ing the usual Encyclopedic pattern of meticulously describing manufacturing 
processes, Deleyre mentioned eighteen separate stages in the manufacture 
of a pin. This article gives us some means of judging how diffused the 


influence of the Encyclopedic could be, even though not always acknowledged. 
Surely it is not simply a coincidence that in the first chapter of the Wealth 
of Nations, Adam Smith illustrates his doctrine regarding the division 
of labor by choosing the now famous example of the lowly pin. One man 
draws out the wire, another straights it, a third cuts it, a fourth points it, 
a fifth grinds it at the top for receiving the head; to make the head requires 
two or three distinct operations; to put it on is a peculiar business, to whiten 
the pins is another; it is even a trade by itself to put them into the paper; 
and the important business of making a pin is, in this manner, divided 
into about eighteen distinct operations . . . 17 

In Volume V Diderot continued his practice of writing long and important 
articles on the history of philosophy, such as his account of the Eleatics. No 
doubt Diderot devoted this liberal amount of space to the leaders of this 
school because their teachings were materialistic. 18 Similarly, the article on 
Epicureanism was long, detailed, and full of loving fondness, although 
it purported to do no more than allow Epicurus to speak for himself. 10 
The article Egyptians gave Diderot the opportunity to declare that Moses 
was a disciple of the Egyptian priests, thereby undercutting the orthodox 
Christian contention that the Mosaic books portrayed original man and the 
earliest societies. Also he could speak disparagingly of priests in general 
while ostensibly discussing the priesthood of pagan Egypt. 20 

Writers of the Enlightenment rather commonly emphasized the antiquity 
of the Egyptians, a point they seem to have learned from Lord Shaftesbury. 21 
This appealed particularly to the philosophes because it permitted them to 
indulge their distaste for revealed religion by insinuating that the laws of 
Moses were simply cultural borrowings. 22 The necessities of polemics there 
fore gave the views of the philosophes, rather fortuitously, an anti-Jewish 
cast. This was a field in which the playful Voltaire loved to caper. The 
Encyclopedic, too, did what it could to attack the fundamentalist assertion 
that the Pentateuch provided the only acceptable and allowable view of 
historical origins. Diderot and his colleagues, because of this dialectical neces 
sity, were unfair to the Jews, unfair in the first place because they were 
insufficiently informed. Diderot, who wrote his article on Jews in 1754, 
would have been more accurate, says Herr Sanger in his monograph on 
this subject, had he consulted rabbis. 23 And the philosophes were unfair in 
the second place because of their inability to appreciate religious genius and 
religious insights in any group. This was an area of human experience in 
which the Enlightenment was likely to be astigmatic. Consequently Diderot 
could interpose in his account of the Jews the following extremely unsym- 


pathetic notice: It will not be useless to warn the reader that one ought not 
to expect to find among the Jews either accuracy in their ideas, or exactitude 
in their reasoning, or precision in their style in a word, anything that 
ought to characterize a sound doctrine of philosophy. On the contrary, 
there is to be found among them only a confused mixture of the principles 
of reason and of revelation, an affected and often impenetrable obscurity, 
principles that lead to fanaticism, a blind respect for the authority of the 
doctors and of antiquity in a word, all the defects indicative of an ignorant 
and superstitious nation. 24 

The article Eclecticism 7 is precious to a biographer because in it Diderot 
allows the reader insight into what he thought of himself. A long and 
quite diffuse article, it is frequently illuminated by flashes of value judg 
ment or by remarks of a very subjective character. Diderot not only defines 
what it is to be an eclectic, he patently thinks himself to be one. For surely 
he does not want to exclude himself from the company that he describes in 
his opening words: The eclectic is a philosopher who, trampling under 
foot prejudice, tradition, vener ability, universal assent, authority in a 
word, everything that overawes the crowd dares to think for himself, to 
ascend to the clearest general principles, to examine them, to discuss them, 
to admit nothing save on the testimony of his own reason and experience; 
and from all the philosophies he has analyzed without favor and without 
partiality, to make one for himself, individual and personal, belonging to 
him. Diderot next asserts what all eclectics emphasize, namely that they 
are not syncretists, a term of opprobrium that an eclecdc uses for any 
eclecticism not his own. Nothing is so common as syncretists, nothing so 
rare as eclectics/ He then discusses the eclectics of the ancient world at 
great length, finding the greatest exemplar to be, of all people, Julian the 
Apostate. (It is a wonder that the censors allowed so much as the mention 
of the Emperor Julian in any context that might be construed as favorable.) 
Modern eclectics, according to Diderot (and with his emphasis), were those 
cultivating experimental philosophy: Eclecticism, this philosophy so reason 
able, which had been practiced by geniuses of the first order long before it 
had a name, remained forgotten until the end of the sixteenth century. 
Then Nature . . . produced at last certain men covetous of humanity s 
finest prerogative, the liberty of thinking for oneself, and the eclectic phi 
losophy was seen to be reborn under Giordano Bruno, Jerome Cardan, 
Francis Bacon, Thomas Campanella, Rene Descartes, Thomas Hobbes . . . 
William Leibniz. . . . 25 Obviously Diderot was calling the roll of names 
among which he hoped posterity would place his own as of a peer. 



Probably the most important single article in the whole seventeen volumes 
of the Encyclopedic was the one written by Diderot on Encyclopedia. By 
its richly textured consideration, first of what an encyclopedia is for, and 
then of an encyclopedia s relationship to language, science, and knowledge 
in general, Diderot s article was comparable in significance and scope to 
D Alembert s Preliminary Discourse. And the two were alike in their 
faith in progress, a faith which was one of the principal tenets in the gospel 
of the philosophy In fact/ wrote Diderot in the first paragraph, c the aim 
of an Encyclopedia is to gather together the knowledge scattered over the 
face of the earth ... that our descendants, being better instructed, may 
become at the same time more virtuous and more happy; and that we may 
not die without having deserved well of the human race. 

There is a printer s mystery regarding this article, for it was published with 
page numbers on the eye-catching right-hand page, but with no pagination 
on the left-hand pages. Thus there are actually thirty-one pages between 
those numbered 633 and 649, a circumstance which naturally makes the reader 
wonder. Could it be that an article half the length was submitted to the 
censors, then one double the length inserted instead? Or was it that Diderot s 
illness delayed him in writing the article? The volume may have had to 
be put in page proof before his article was ready; but the article may have 
turned out to be twice as long as planned for, thus necessitating this unusual 
procedure. 26 

The article Encyclopedia is a little book in itself, some 34,000 words in 
length Such are the first ideas that offered themselves to my mind, wrote 
Diderot in closing on the project of a universal and systematic dictionary 
of human knowledge: on the possibility of it, its object, the arrangement 
of its materials both general and detailed, its style, method, cross references, 
nomenclature, its manuscript, authors, censors, editors, and typography. It 
can well be imagined that when Diderot spread his net so wide, he caught a 
lot of fish. For instance, he descanted at length in the early part of the 
article on problems of linguistics. Profoundly impressed with how difficult 
it is to achieve accurate definitions, he wrote more like the scientist than 
like the creative artist who knows that words are symbols or hieroglyphs 
and therefore cannot be completely fixed. For he knew that the increase of 
knowledge necessitates an accurate and expanding vocabulary to implement 
it and he hoped that the Encyclopedic or a similar venture could assist in 
the fixation of language. This would be extensive, including not only all 
aspects of definition but even an analysis of sounds and a drastic orthographic 


reform by which spelling would become completely phonetic. In illustra 
tion he compared the current French and English phonetic rendering of a 
line of Greek verse, and in so doing conceived of something closely resembling 
the alphabet of the International Phonetic Association. Diderot may there 
fore be considered one of the pioneers in the emergent science of linguistics, 
although a modern expert has remarked, as a linguistic theorist his mind 
was of too meteoric a nature to submit to that patient discipline, that 
laborious exploration of linguistic facts which alone were capable of laying 
the foundations of a science of language. 27 

Diderot disarmed critics of the Encyclopedic by candidly acknowledging 
defects. First he invited his reader to visualize the problems involved in se 
curing a proper balance and proportion among the multitudinous articles 
in the work. Even if one man could write every entry, the problem would 
still be formidable. And he who supposes that he has taken precautions with 
his colleagues so that the contributed material will square approximately 
with his plan is a man who has no idea of his object or of his colleagues. 
Some contributions will be too laconic, some too prolix. The proof of it is 
evident in a hundred places in this work. ... In one place we are like 
skeletons; in another, we have a dropsical appearance. We are alternatively 
dwarfs and giants, colossi and pygmies; erect, well-made, and well-pro 
portioned, humpbacked, limping, and deformed. As for the prolixity of 
some of the articles, emulation among the contributors had the effect of 
producing dissertations instead of articles. Time and subsequent editions 
would take care of this. Besides, new inventions and new ideas necessarily 
introducing a disproportion; and the first edition being, of all, the one con 
taining the greatest number of subjects that, if not newly invented, are 
at least as little known as if they had this characteristic, it is evident . . , 
that this is the edition in which will reign the most disorder, but which, on 
the other hand, will exhibit, through all its irregularities, an original air 
that only with difficulty will pass over into subsequent editions.* 2S 

Diderot was not so fatuous as to suppose that the Encyclopedic would not 
be superseded: If our dictionary is good, how many works will it produce 
that are better! 29 Repeatedly he wrote of the necessity of succeeding editions, 
as when he said explicitly that the first edition of an encyclopedia can be 
only a very incomplete and formless compilation. 30 These admissions, as 
also the one about being either skeletal or dropsical, were promptly seized 
upon by his enemies, though this self-criticism has enhanced rather than 
decreased the estimation of the work by impartial critics. Diderot was never 


in doubt about the project itself, however, and constantly spoke of it in the 
ringing tones of a man who believes that the spread of knowledge will make 
mankind happier and better. 

Occasionally in this long article Diderot allowed his reader to glimpse some 
of the editorial problems that had to be contended with: I examine our 
work without partiality; I see that there is perhaps not a single sort of error 
that we have not committed; and I am forced to admit that of an Encyclo 
pedic like ours, scarcely two-thirds of it would be included in a true Ency 
clopedia. That is a great deal, especially if one acknowledges that in laying 
the first foundations of such a work, one was forced to take for a basis some 
inferior author or other, whether Chambers, Alsted, or some other. There 
is almost no one of our colleagues who could have been persuaded to work, 
if it had been proposed to him to compose all his assignment from the be 
ginning; each would have been intimidated, and the Encyclopedic would 
not have been done. But by presenting to each one a roll of paper that had 
only to be re-examined, corrected, expanded, the work of creating, which is 
always what one dreads, disappeared and each, from a presumption that 
could not have been more chimerical, allowed himself to engage to do the 
work; for these disconnected fragments were so incomplete, so badly written, 
so poorly translated, so full of omissions, errors, and inaccuracies, so contrary 
to the ideas of our colleagues, that most of them threw them aside. Would 
that they had all had the same courage! . , . How much time lost in trans 
lating inferior things! What expenditures in order to obtain a continual 
plagiarism! S1 Elsewhere Diderot remarked on his colleagues propensity 
to quote verse, an inclination he discouraged save in articles on literary 
subjects; on the prolixity of contributors, encouraged, if not justified, by 
the editors own; on the difficulty, and yet the importance, of keeping a 
proper balance; on the impracticability of insisting that the entire manu 
script be turned in before the printing was begun, with consequent blunders 
and omissions in regard to cross references; and on the very particular 
difficulty of getting accurate information about the arts and crafts. 32 Re 
garding this last difficulty, he wrote: But as the arts have been the principal 
object of my work, I am going to explain myself candidly, both concerning 
the mistakes I have made and the precautions that would need to be taken 
to correct them. 

He who would take upon himself the subject matter of the arts will not 
acquit himself of his labors in a satisfactory manner either for others or 
for himself, if he has not profoundly studied natural history, especially 
mineralogy; if he is not an excellent mechanic; if he is not well versed in 


theoretical and experimental physics; and if he has not taken several courses 
in chemistry. 33 

These rigorous requirements of an editor were more than hypothetical 
to Diderot for at this very time he was attending the lectures and demonstra 
tions given at the Jardin du Roy by Rouelle, the leading French chemist 
of his day. For three consecutive years Diderot attended these lectures, and 
copies of the notes he took are still in existence. 34 In addition, he wrote a 
very engaging and informative character sketch of this eccentric and single- 
minded scientist. 35 

Having launched on a discussion of all the qualifications necessary to 
one hopeful of describing the arts and crafts, Diderot particularly mentions 
the problem of securing information from craftsmen: He [who would 
correct the articles on the arts] will not be long in perceiving that, in spite 
of all the care we have taken, there have slipped into the work some gross 
blunders (see the article "Brique"), and that there are whole articles that 
do not have a shadow of common sense (see the article "Blanc his serie de 
toiles"} ; but he will learn by his own experience to thank us for the things 
done well and pardon us for those done ill. Especially will he learn, after 
having for some time gone from workshop to workshop with cash in his 
hand and after having paid dearly for the most preposterous misinformation, 
what sort of people craftsmen are, especially those at Paris, where the fear 
of taxes makes them perpetually suspicious, and where they look upon any 
person who interrogates them with any curiosity as an emissary of the tax 
farmers, or as a worker who wants to open shop. 36 

It was in this article that subscribers were first told about the engravings 
that were to illustrate the work, none having yet been published. Diderot 
announced that we have about a thousand plates. 5 The account book of the 
publishers shows that there had indeed been much activity in this depart 
ment, with disbursements beginning in 1748. In 1751, very frequent and sub 
stantial payments began, especially to a man named Goussier, who ultimately 
did the drawings for more than nine hundred of the finished plates. 37 More 
over, they were superior ones. In spite of the prodigious number of figures 
that fill them, we have paid attention to admitting scarcely any that do not 
represent a machine now in existence and working. Let our volumes be 
compared with the collection of Ramelli [1588] which is praised so highly, 
the Theatrum machinarum [1724-7] of Leupold, or even the volumes of 
machines approved by the Academic des Sciences, and then one can judge 
whether, of all these volumes put together, it would be possible to take 
twenty plates from them worthy of inclusion in such a collection as we 


have had the courage to conceive and the good fortune to execute. There 
is nothing here that is superfluous or superannuated or imaginary: every 
thing in it is in action and alive/ 38 

This was the first occasion but not the last when the engravings 
done for the Encyclopedic and those for the Royal Academy of Sciences 
were contrasted and compared. In 1675 Colbert, the great minister of Louis 
XIV, had requested the Royal Academy to publish a series of illustrations 
and explanations concerning the machines used in the arts and crafts, 39 The 
preparation of these drawings and engravings continued sporadically and 
dilatorily for decades, with Reaumur more responsible for them than anyone 
else; and the result was that the Encyclopedic was announced and its pub 
lication far advanced before the Academy of Sciences, under the spur of 
competition, finally published its first fascicle, that on Charcoal Burning, 
in 1761. 

Meanwhile Diderot and the publishers of the Encyclopedic had procured 
for their examination and comparison copies of a good many of the various 
Academy prints that had been engraved but not yet published. Diderot 
says as much in the passage just quoted, and it is unlikely that he would 
have called attention to this proceeding, and in so public a way, if he had 
supposed that there was anything dishonest about it. 40 Reaumur, however, 
evidently regarded it so and said as much to Formey who, about this time, 
was toying with the idea of editing an encyclopedia himself. 41 Apparently 
he had written to Reaumur inquiring about engravings, for the latter replied 
on 23 February 1756, 1 have had more than a hundred and fifty plates 
engraved in folio size, they being very pleasing pictures, and I have many 
others that are only drawings. I could have made the whole literary world 
resound with my cries over the theft that has been done me of the first- 
named and taken steps to have justice done. The infidelity and negligence 
of my engravers, of whom several are dead, have made it easy for people 
with little delicacy regarding their methods to collect proofs of these plates, 
and they have been engraved anew in order to insert them in the encyclo 
pedical Dictionary. I have learned somewhat tardily that the fruits of so 
many years of labor have been taken away from me. I have preferred to 
appear to be ignorant of it than to trouble my repose by reclaiming my 
property. The only other time he had ever discussed the matter, Reaumur 
went on to say, was in a letter to his friend the German metaphysician 
Christian Wolff, now dead two years. 42 

It is hard to pronounce upon the amount of moral turpitude involved in 
this incident. If Reaumur was convinced that a serious theft had occurred, 


how does it happen that he regarded it as a matter that concerned only 
himself and not the Academy of Sciences? Moreover, he writes to foreign 
scholars about it, but evidently takes care not to say anything about it in 
France, alleging a desire to keep his peace of mind. But if a theft had really 
occurred, it would certainly seem that an investigation was in order. Indeed, 
this was precisely what the publishers of the Encyclopedic demanded at 
once when the allegation of theft and plagiarism was made public in 1759, 
two years after Reaumur s death. As a result, the official commission of the 
Academy of Sciences testified that we have recognized nothing in the 
Encyclopedic prints that was copied after the plates of M. de Reaumur. 43 
There is no question that Diderot and his publishers had had in their pos 
session some of the Academy of Science proofs, depriving Diderot of the 
right to claim credit for originating plans for the attractive drawings in 
perspective illustrating the processes in each art or craft. Both works used 
this device, and the Academy of Sciences can clearly claim priority. But 
unless there was intent to defraud, there could be no moral turpitude in 
possessing some of the proofs of a languishing enterprise that had been 
begun seventy-five years previously and had not even yet made any an 
nouncement of intending publication. 44 

Diderot s discussion of the Encyclopedias cross-reference system in his 
article Encyclopedia is amazingly frank. He explained at great length the 
organic relationship of subjects that the editors hoped to accomplish by the 
skillful use of cross references and, surprisingly enough, he described with 
complete candor the ideological purpose of the Encyclopedias system. For 
cross references can be used, he wrote, to contrast conflicting principles and 
to overthrow ridiculous opinions that cannot be frontally attacked. The 
entire work would receive [from such cross references] an internal force 
and secret utility, the noiseless effects of which would necessarily become 
perceptible with time. For example, every time a national prejudice requires 
respect, it should respectfully be set forth, at the appropriate place, with all 
its accompaniments of verisimilitude and seduction; but the edifice of mud 
ought to be overthrown, the useless accumulation of dust be dissipated, by 
referring to articles where solid principles serve as a basis for opposing 
truths. This manner of disabusing men operates very quickly upon good 
understandings; and it operates infallibly on every mind and without dis 
agreeable consequences, secretly and without creating a sensation. It is the 
art of tacitly deducing the most radical conclusions. If these cross references 
of confirmation or refutation are foreseen far ahead of time and prepared 
with skill, they will give to an encyclopedia the character that a good die- 



tionary ought to have, namely the character of changing the general way 

of thinking. 45 

It seems clear that Diderot had France s established religion in mind when 
he referred to a national prejudice. His revelation of the uses to which his 
cross references were put not unnaturally had repercussions. It was made 
the subject of a considerable amount of animadversion, as was also an in 
cidental remark of his that caused the Archbishop of Paris to write in 
protest to Malesherbes. I join to my letter/ wrote Christophe de Beaumont, 
<a note of what is to be read in the fifth volume of the encyclopedic dictionary, 
page 635 at the word "Encyclopedia " You will see that the Sorbonne is 
therein spoken of in a very indecent manner by asserting that it could 
furnish to the Encyclopedic only theology, sacred history, and superstitions. 
To regard the science of religion as a source of superstition is to attack 
religion itself. It is very regrettable that the censors did not notice an error 
like this, and I hope that you will have no objection to giving the necessary 
orders so that it may be corrected or at least amends be made. 4G Amends 
of a sort were made. The list of errata in Volume VI declared that the 
passage, which contrary to our intention some persons have found am 
biguous, should read Geology, sacred history, and the history of super 
stitions. Diderot s explanation, which in reality rendered his original motives 
more inscrutable than ever, did not reveal a high degree of penitence. 

Of course when Diderot allowed himself to speak this way about the 
Sorbonne, he was thinking of the troubles involving the Abbe de Prades. 
This is but one instance of his using the article Encyclopedia as a vehicle 
for the expression of his animosities, his likes, and his personal ambitions. 
He begins and ends his long article by sneering at the Jesuits and their 
Dictionnaire de Trevoux; he asserts aggressively that among those who 
have set themselves up for censors of the Encyclopedic, there is scarcely one 
with the talent necessary for enriching it with one good article ; he scolds 
the French Academy for not finishing its dictionary and then broadly hints 
that he would be capable of doing so himself if he were a member; he breaks 
forth in praise of a personal friend *O Rousseau! my dear and worthy 
friend ; he boasts of having taught his fellow citizens to esteem and read 
Francis Bacon; he apologizes for himself, managing to praise himself at 
the same time, and betrays his true opinion of himself, one feels quite sure, 
as he defines his conception of the ideal editor for a work of this sort. *A 
man endowed with great good sense, celebrated by the breadth of his 
knowledge, the elevation of his feelings and conceptions, and his love for 
work; a man loved and respected both for his private and his public char- 

This engraving (1763) from the Encyclopedic illustrates articles on the craft 
of cutlery written by Diderot himself. Tile shop shown is that of a Parisian 
cutler rather than the establishment of Diderot s father at Langres. 


acter; never a frenzied enthusiast, save for truth, virtue, and humanity. 5 47 
Truth, virtue, and humanity! Shining words. In their names Diderot led 
the assault upon minds apprehensive of change and defended himself from 
the allegations that he was subversive and unvirtuous. Diderot s enemies, 
and the enemies of the philosophes in general, constantly maintained that 
religious orthodoxy and right conduct were inseparable, and that one could 
not truly have the one without the other. This Diderot, believing as he did, 
emphatically denied, and he was always at pains to insist that to be a 
philosophe was necessarily to be virtuous. He never tired of asserting his 
probity and proclaiming his virtue, or of calling himself a good man, an 
homme de bien. Partly, perhaps mostly, it was because he was convinced 
of it; partly it was to combat the narrow-mindedness of those who would 
like everyone to believe that an unorthodox man must necessarily be a 
vicious one. 

The moral note is struck more than once in Diderot s article Encyclopedia. 
He speaks of inspiring the taste for knowledge, the horror of lying and 
of vice, and the love of virtue; for whatever has not happiness and virtue 
for its ultimate end is nothing, and later on he remarks that it is at least 
as important to make men better as to make them less ignorant. 5 4S There 
is in Diderot s manner of thinking a constant relating of truth to man and 
the ends of man. Truth not only exists of itself: it becomes usable only 
when humanly apperceived. This pronounced humanism in Diderot s thought 
so pronounced that it has appropriately given the title L Humanisme de 
Diderot to one of the best critical works concerning him is well expressed 
by a passage in the article Encyclopedia : A consideration that above all 
must not be lost from view is that if man, or the thinking and contemplative 
being, is banished from the surface of the earth, this pathetic and sublime 
spectacle of nature becomes nothing but a mute and melancholy scene. . . . 
Why not [therefore] introduce man in our work as he is placed in the 
universe? Why not make of him a common center? . . . Man is the sole 
and only limit whence one must start and back to whom everything must 
return, if one wishes to please, interest, touch, even in the most arid con 
siderations and the driest details. Setting aside my own existence and the 
happiness of my fellow beings, what does the rest of nature matter to me? 49 
This insistence that knowledge to be meaningful must be related to man 
made of Diderot something more than a scientist some people might say 
it made him less than one. But Diderot s humanism explains why he is so 
interested in ethics, why the search for the bases of moral sanction has for 
him so great a fascination. The ideal of the philosophe, as Diderot accepted 


it for his Encyclopedic article Philosopher, was humanistic and social, the 
ideal of a thinker interested in his fellow man. Now, because this ideal was 
so humanistic and social and so little religious or theological Diderot 
time and again appealed for his ultimate justification to the unprejudiced 
judgment of his peers. And since contemporaries are likely to be prejudiced, 
Diderot turned to posterity for the comforting sense of ultimate justification. 
Thus, after describing all the difficulties attendant upon completing an 
encyclopedia, he writes: We have seen that the Encyclopedie could be the 
effort of only a philosophical century; that this century has arrived; that 
renown, while carrying to immortality the names of those who will finish 
it, will perhaps not disdain to take care of ours; and we have felt our 
selves reanimated by an idea so consoling and so sweet, that we too shall 
be spoken of when we shall no longer exist; [reanimated] by this captivating 
murmur which gives us to understand, from the lips of some of our con 
temporaries, what shall be said about us by men to whose instruction and 
happiness we have sacrificed ourselves, whom we have esteemed and loved 
although they are not yet born/ 50 

Posterity shall judge, wrote Diderot. 51 For posterity, in Diderot s eyes, 
was the supreme court. 


Growing Tension with Rousseau: 
Only the Bad Man Lives Alone 

DIDEROT was a man expansive in temperament and 
rich in the outpourings of his imagination, sym 
pathy, and sensitivity. Yet he also had a vein of cool and unemotional 
scientific objectivity which almost always came into play when his meta 
physical views were at stake. An example of this capacity to remain detached 
when others are suffering is shown by his neutral attitude toward the greatest 
public disaster of the eighteenth century. Many of his contemporaries were 
saddened, their fondest convictions - undermined, by the earthquake at 
Lisbon on i November 1755 which wiped out the lives of many thousands 
within a few minutes. The earthquake not only shook Lisbon, it shook 
Voltaire, who had been living in a rather happy deistic faith. The impassive 
inscrutability and indiscriminacy of the event caused Voltaire to question 
shudderingly God s ways to man. To this questioning we owe Candide. 
But it is characteristic of Diderot, with his strictly naturalistic conception 
of a universe that he thought could be explained without having to pred 
icate God, that the Lisbon earthquake presented him with no intellectual 
problem whatever. 1 

In the following year Frederick the Great precipitated the Seven Years 
War by his incursion into Saxony. This was the war that saw the exploits 
of Montcalm and Wolfe in Canada and of Clive in India, a war which 
permanently affected the political destinies of a considerable fraction of 
mankind. This was the year of the Diplomatic Revolution, when France, 
since the days of Cardinal Richelieu the archenemy of the Hapsburgs, re 
versed her alliance system and became the ally of Maria-Theresa. It was 
the beginning of a war in which the luster of French arms at first was 
brightened by the capture of Port Mahon, only to be tarnished by the 



humiliation of Rossbach; a war in which the monarchy o Louis XV and 
Madame de Pompadour frittered away the substance of colonial and mari 
time power in exchange for some vague dream of Continental hegemony. 
The prestige and the finances of France suffered grievously in the Seven 
Years War, and it may be accounted one of the predisposing causes for the 
later alliance with the infant United States, for instance, as well as for the 
Revolution of 1789 itself. Militarily and intellectually, the decade of the 
fifties was the decisive one in the history of France in the eighteenth 


It is surprising to find Diderot scarcely aware of the Seven Years War 
or its implications. He, a leader in one of the two great changes occurring 
in the life of his time, was oddly insensitive to the other. Save for the incident 
in his Fils naturel of the capture and imprisonment of Rosalie s father by 
the British plus a reference in his Pere de jamille to an episode in the Port 
Mahon campaign, neither Diderot s writings nor his letters refer to the 
war. It seems to have affected him only in regard to Grimm, who was attached 
to the staff of a French marshal for a few months in 1757 on campaign in 
Westphalia. 2 During these years of 1756-63 we shall hear much of Diderot s 
tribulations, for this was the time of his greatest trials and, in view of his 
spirited conduct in the face of great adversity, his nearest approach to heroism. 
And as if his personal life had absorbed all his energies, he lived through 
these years as though buffeted by everything except the war itself. 

Diderot s correspondence in 1756 shows him now and again in that mood 
of heated and self-righteous expostulation that he easily fell into, and there 
is a note of distinct acerbity and irritability in his relations with people at 
this time that may be a symptom of overwork or a consequence of lingering 
ill health. One of these occasions had to do with a lawsuit over the appoint 
ment to a priory in which his younger brother, the Abbe, had become in 
volved. Mme de Vandeul says that her father put himself to incredible 
trouble in accommodating this matter, and we see Diderot working on 
it in a couple of letters written to his litigious and unconciliatory brother. 
Of the Abbe s opponent Diderot wrote, *I believe M. le Chevalier a very 
honest man, even though he be a good Christian ! And a few days later, 
washing his hands of the affair, Diderot wrote, You have written me the 
letter of a litigant and a fanatic. If these are the two qualities that are con 
ferred upon you by your religion, I am very content with mine, and I 
hope not to change it. 3 No doubt the Abbe Diderot was a very difficult 
person, but letters like this were scarcely calculated to sweeten the temper. 

Another of these expostulatory outbursts occurred in a long letter written 


by Diderot in the summer of 1756 to a contributor to the Encyclopedic, 
probably Paul Landois. 4 Landois was an obscure writer of whom very little 
is known save that he wrote a one-act tragedy in 1742, Sylvie by name, which 
was in prose and dealt with the affairs of run-of-the-mill humanity, not 
personages of exalted rank. This tragedy, with its one act, its ordinary people, 
its prose, and its explicit stage directions, flouted so many of the established 
traditions of the French theater that it deserves remembering as an early 
exemplar of the reforms that Diderot expounded fifteen years later. In 
1756 Landois, who contributed a few unimportant articles concerning paint 
ing for the Encyclopedic, was evidently seven to eight days post-time away 
from Paris and fuming at not being paid so promptly as he wished. It 
is clear from the nature of Diderot s letter that Landois was an extremely 
temperamental man much given to supposing that he was greatly put upon. 
In order to correct this impression, Diderot wrote him at great length, 
attacking the problem on three successive levels. The first was Diderot s 
personal disclaimer of guilt; the second was a discussion of Landois way 
of comporting himself, viewed in the light of conventional morality; the 
third was a discussion of Landois behavior from the point of view of phi 
losophy. Inasmuch as this letter provides what appears to be a clear-cut 
statement of Diderot s views on ethics, it is frequently and extensively 

On the first level Diderot proceeds upon the theory that the best defense 
is a strong offense. Now, let s come to the business of your manuscript. It 
is a work capable of ruining me. After having charged me twice with the 
most atrocious and most deliberate outrages, you propose to me the revision 
and printing o it. ... You take me for an imbecile or you are one your 
self * 

Having generated a sufficient amount of heat, Diderot passes to the 
second level of the argument by reproaching Landois for his detestable 
morality, and then, describing his own code of ethics: I find in myself an 
equal repugnance to wrong reasoning and wrong doing. I am between two 
forces, one of which shows me the good and the other inclines me toward 
evil. One must choose. At the beginning the moment of struggle is grievous, 
but the intensity of it weakens with time. There comes a time when the 
sacrifice of one s passion no longer costs a pang. I can even certify from 
experience that it is pleasant: one takes on in one s own eyes so much 
stature and dignity! Virtue is a mistress to whom one is attached as much 
by what one does for her as by the charms one believes her to possess. Woe 
to you if the practice of doing good is not sufficiently familiar to you, and 


if you have not accumulated a sufficient stock o good actions to be vain 
of them, to compliment yourself about them ceaselessly, to intoxicate your 
self with this heady vapor and be fanatical about it. 

"We take virtue," you say, "the way a sick man takes medicine," to 
which, if he were well, he would prefer any other thing that would please 
his appetite. That is true of a sick man out of his senses: but in spite of 
that, if this sick man had had the merit of diagnosing his malady himself, 
of having discovered and prepared the medicine for it, do you think he 
would hesitate in taking it, however bitter it was, or that he would not 
compliment himself for his acumen and courage? What is a virtuous man? 
It is a man vain with this sort of vanity, and nothing more. . . . This is 
an unusual definition of a virtuous man, and might be considered an extraor 
dinarily debunking one. But Diderot suggests that nevertheless Landois 
weigh the advantages such people gain for themselves, and especially what 
disadvantages they avoid. Thus Diderot argues that virtue is the pursuit of 
happiness, a kind of utilitarianism in which pleasure is strongly compounded 
of the esteem that others express for one as well as the esteem of oneself: 
But if ever you undertake [this calculation], do not forget to estimate for 
all that they are worth the esteem of others and that of oneself. Moreover, 
do not forget that a bad action never goes unpunished. I say never, because 
the first one that one commits inclines one to a second, that one to a third, 
and thus one advances step by step toward being held in contempt by one s 
fellow men, the greatest of all evils. 

Diderot now comes to the third level of his argument. His object is to 
cure Landois of supposing that the whole of nature conspires against you, 
that chance has heaped up all the kinds of misfortune in order to pour 
them on your head. Where the devil did you get such pride? My dear 
fellow, you prize yourself too highly, you grant yourself too much importance 
in the universe. In order to disabuse Landois of so much pride, Diderot 
says of himself that he must leave off the tone of the preacher to take up, 
if I can, that of the philosopher. For now comes a discussion of the relation 
ship between morality and determinism. Diderot believed that effect follows 
cause so inexorably in the training and experience of the human being that 
liberty* is a meaningless word. The context would seem to indicate that he 
uses the word liberty in the sense of unpredictability or caprice. At all 
events, this important passage is as follows: Look at the matter closely and 
you will see that the word "liberty" is a word devoid of sense; that there 
are not, and cannot be, free beings; that we are only what is in consonance 
with the general order, with our organization, education, and the chain 


of events. That is what disposes of us invincibly. One can no more conceive 
of a being acting without motive than one can of the arm of a scales acting 
without the action of a weight, and the motive is always external to us, 
foreign to us, brought on by some nature or some cause that is not we our 
selves. What misleads us is the prodigious variety of our actions, joined 
with the habit we contracted as soon as we were born of confusing the 
voluntary with the free. . . . 

It will be noticed that Diderot is expressing a theory of ethics that includes 
both heredity and environment: in his words, organization and education. 
Moreover, he recognizes that human beings have wills and exercise them, 
but he denies that human beings can exercise their wills capriciously and 
without relation to the totality of cause and effect in their previous experi 
ence. This is a conception of man s moral nature as full of horse sense as 
of philosophy. Diderot conceives of ethics as a scientific matter, effect inex 
orably related to cause. By such determinism he conceives of human conduct 
in a fashion that avoids the uncertainty and the insecurity of a theory of 
moral indeterminism in which anything can happen, even the most chaotic, 
the most unlikely, or the most unpredictable. 5 A wholly free will in a 
finite world is a fair definition of insanity/ writes a modern author. 6 The 
point was, according to Diderot, that Landois could not suddenly cease 
at will to be evil. After having made oneself bad, is being good merely a 
matter of removing oneself a hundred leagues, or of saying to oneself, I 
want to be? The crease is set, and the cloth has to keep it. 

Far from feeling that nothing can be done in the moral training of 
human beings, Diderot emphasizes that although the beneficent or the 
maleficent man is not free, man is none the less a modifiable being. It is 
for this reason that the maleficent man should be destroyed at a place of 
public execution. From this fact [of his being modifiable, derive] the good 
effects of example, precepts, education, pleasure, pain, grandeur, poverty, 
etc.; from this fact, a sort of philosophy full of commiseration, attaching one 
strongly to good persons, but irritating one against a bad one no more than 
against a hurricane that fills our eyes with dust/ 

Diderot is here describing a system of morality that operates independently 
of the hope for reward or the fear of punishment in another world. Per 
haps it is the positive and this-worldly aspect of his doctrine that causes 
him to avoid relying upon the ordinary criteria of virtue and vice : 
But if there is no liberty, there is no action meriting praise or blame, 
no vice nor virtue, nothing that must be recompensed or chastised. What 
then distinguishes men? Doing good and doing evil. The evildoer is a man 



to be destroyed, not punished. Beneficence is a good fortune, not a virtue/ 
This way o stating moral doctrine seems harsh and forbidding, and in 
consequence the letter to Landois is very often cited as proving that Diderot s 
ethics had a hard, machinelike character, divesting human life of choice. 
But if one judges moral conduct from the point of view of results instead 
of from the point of view of intention, then Diderot s doctrine does not 
seem nearly so strange. His emphasis is then seen as one of social utility. 7 
Good conduct, according to such a view, depends upon doing, upon the 
concrete and positive results of moral action. But man still remains a 
modifiable being capable of exercising choice. Diderot proves that he be 
lieves this by saying in the next few lines of the letter, Adopt these prin 
ciples if you find them good, or show me that they are defective. If you 
adopt them, they will reconcile you with others and with yourself. 

While Diderot was engaged in this troublesome quarrel with Landois, his 
relations with other friends were also suffering deterioration. Probably there 
was some sort of quarrel with Condillac, to judge by Grimm s sudden and 
venomous attack after having praised Diderot s former friend only a little 
previously. Diderot and Condillac had not been intimate for some years 
and were now far removed from the days of the dinners at the Panier 
Fleuri. Their relations were further chilled, about this time, because Diderot 
felt that Condillac had pilfered from the Letter on the Deaf and Dumb 
(1751) one of the main ideas for his Treatise on Sensations, which appeared 
three years later. 8 

Coincident with this turbulence in Diderot s relations with his friends 
was, it seems, a delay in the publication of the sixth volume of the Ency- 
dopedie. For although Grimm remarked in his news letter of i May 1756 
that the volume had just been published, a friend wrote to Rousseau from 
Paris on 23 September that it had not yet appeared. 9 Diderot himself speaks 
of being in the country seeking rest and health after having completed the 
sixth volume, and the same correspondent of Rousseau dates this villeggiatura 
exactly by writing on 16 September that Diderot had just returned to Paris 
from a three-weeks visit at the country house of Le Breton, his publisher. 10 
This delay in publication, if delay there was, may have contributed to 
Diderot s apparent irritability of that year, although the tardiness may 
have been caused by Diderot s lingering ill health. Le Breton carried him 
away from Paris for a vacation; yet even after that Diderot suffered a very 
bad attack of colic, which he attributed to his injudiciously discontinuing 
his diet of milk. 11 
When Volume VI finally appeared it was the least controversial of all the 


early volumes of the Encyclopedic and seems to have pleased everyone but 
Voltaire. The volume contained important articles by Turgot on Etymology/ 
Expansibility/ and Existence/ the latter a masterly exposition of the intel 
lectual presuppositions shared by most of the Encyclopedists. Then there 
were articles on Evidence/ Fetes/ Fireworks/ Fiefs/ Fevers/ Finances/ 
Fluid/ Flute/ and so on, the usual sort of intake of a work that called itself 
a methodical dictionary of the sciences, arts, and crafts. Especially note 
worthy was Quesnay s long article on Farmers (Fermiers), an article that 
has recently been called by a Marxist writer the origin of the whole physio- 
cratic doctrine because it analyzes the role of capital in production. 12 
Diderot s share as a contributor of articles was distinctly less in this than in 
the other volumes, a circumstance which may have been owing to his ill 
health. Voltaire contributed fifteen articles and, in direct proportion to his 
becoming more closely identified with the work, grew correspondingly con 
cerned about its all too patent unevenness. 

Voltaire had not originally been a subscriber to the Encyclopedic, so 
that he praised it, to begin with, more on hearsay than on firsthand knowl 
edge. 13 He liked to refer to Diderot and D Alembert as Adas and Hercules, 
carrying the world on your shoulders. 14 The Encyclopedic was the greatest 
and finest monument of the nation and of literature ; he adjured D Alem 
bert to hasten to finish the greatest work in the world. 15 Symbolic of their 
growing association was D Alembert s visit to Voltaire during the summer 
of the year in which Volume VI was published. It was during this very 
successful stay that Voltaire suggested D Alembert write an article on Ge 
neva/ an article which was to cause much trouble when it was published 
in Volume VII. 16 After D Alembert s return to Paris, Voltaire s letters be 
came much more frank than they had previously been. What I am told about 
the articles on theology and metaphysics wrings my heart. It is grievous 
to print the contrary of what one thinks. 

I am also sorry that people write dissertations and give private opinions 
for established truths. I should like definition and the origin of the word, 
with examples, everywhere. 17 

A month later Voltaire professed himself unable to believe that in so serious 
a work the following sentence had appeared in an article on Femme : 
Chloe presses her knee against one beau while rumpling the lace of another. 
What the writer, a man named Desmahis, had really said about Chloe 
was not much better: she presses her knee against one, squeezes the hand 
of another while praising his lace, and at the same time tosses off some 
suitable words to a third. Voltaire remarked of this article that it must have 


been written by the lackey of Gil Bias. 18 To this D Alembert replied by 
a personal exculpation these articles are not in my bailiwick and added, 
Besides, I owe my colleague the justice o saying that he is not always in a 
position to reject or condense the articles presented to him/ 19 This par 
ticular aspect o the correspondence was then brought to an end by Voltaire s 
very sensibly inquiring, Why have you not recommended a sort of instruc 
tion sheet for those who serve you, etymologies, definitions, examples, reason, 
clarity, and brevity? 20 

During 1756 the friendship of Diderot and Rousseau moved into a 
penumbra that was close to eclipse. Even the play that Diderot was writing 
that autumn, his Fils naturel (The Natural Son ), was destined to figure 
in this melancholy tale. The story of their friendship s end is tangled and 
complicated, hot with the passion of their clashing certainties of being in the 
right, mournful in the slow and inexorable ruin of their delight in each 
other. There is something epic and something symbolic in the confused, 
nightmarish deliquescence of their friendship, epic because of the intensity 
and vividness of the personalities of these two men, and epic, too, because 
of their articulateness. Symbolic it was in that the differences dividing them, 
although they did not realize it, were ideological. Rousseau was the precursor 
of Robespierre, Diderot of Danton, and a generation later one sent the other 
to the guillotine. The personal and temperamental irritations occurring 
during 1756-8 were exacerbated by profound and little-understood discrep 
ancies in their outlook on life. These twisted their judgments and are likely 
to twist the judgments of their biographers, too, for it is almost impossible 
to watch the wavering scales of justice and refrain from jumping into one 
of the pans. Temperament and circumstance combine so momentously that 
detached judgment becomes difficult. We tend to be Rousseau-men or 
Diderot-men, just as we tend to be Hamilton-men or Jefferson-men, Erasmus- 
men or Luther-men, Caesar-men or Cicero-men. 

Rousseau always claimed that the revelation that came to him on the road 
to Vincennes in 1749 marked the turning point of his life. This was the 
revelation, glowing within him with the incandescence of a truth believed 
self-evident, that man s fate had become worse as his life had grown more 
sophisticated and more complex. It was a revelation such as might con 
ceivably come to a young man reared in puritanical simplicity on the shores, 
say, of Lake Tahoe, who comes to the metropolis to make his mark and 
lives precariously there, never quite at home and a success, never quite 
beaten and a failure, never quite sure enough of himself to be openly cen 
sorious of the life about him. The revelation of 1749 gave Rousseau the 


courage of his previously unasserted convictions. He still was sensitive, 
over-serious, and humorless. But these temperamental qualities now focused 
on what seemed to him the artificiality and conventionality of Parisian life. 
His friends could scarcely fail to notice his discontent. Their mistake was to 
suppose it merely superficial or even insincere. 

It was not just with Paris that Rousseau was discontented. His friends, or 
most of them, galled him. He resented Diderot s unsolicited advice about 
accepting the King s pension; he suspected D Holbach of trying to make 
people believe that Rousseau had plagiarized the music for the Village 
Soothsayer; he disliked the philosophes baiting of the Abbe Petit, the man 
who had the theory of how to write a play in five acts; and he particularly 
abominated, as his preface to his play Narcisse shows so well, the anti- 
religious philosophy of his own circle of friends. When, therefore, the 
wealthy Mme d Epinay, a lady whom he had known since 1747, offered 
him the occupancy of the Hermitage, a spacious and specially remodeled 
cottage on her estate near Montmorency, ten miles to the north of Paris, 
Rousseau allowed himself to be persuaded to get away from it all. 21 His 
friends, regarding his decision as a ludicrous whim, loudly predicted that 
he could not endure it a fortnight. Sarcasms fell on me like hail, Rousseau 
later recalled in his Confessions. On 9 April 1756, he began living at the 
Hermitage, vowing never to live in cities again. 

There is no doubt that Rousseau s friends were disconcerted by his leaving 
Paris, and even more so by his remaining away. Life away from Paris hardly 
seemed worth living to that intensely sociable age, especially if compounded 
by solitude. Paris and, for courtiers, Versailles seemed to most persons who 
had lived in them the only really habitable places in France. This feeling is 
reflected in the word the eighteenth century used when the king deprived 
a minister of his office and commanded him to live upon his country estate 
until further orders. The eighteenth century always said that a minister 
in such circumstances was exiled, as if living in a country house or chateau 
were equivalent to being banished to the ends of the earth. Rousseau s self- 
exile, as the D Holbach circle thought of it, might be construed as a standing 
reproach to them, and was therefore a constant and subtle irritation. If he 
was wise, they were foolish. Moreover, if his exile was virtue, then it cast 
doubt on their mode of life. This they found intolerable, so that Diderot 
put into the mouth of one of the characters in his Fils naturel this extremely 
barbed and personal allusion: *I appeal to your heart: ask it, and it will tell 
you that the good man lives in society, and only the bad man lives alone. 22 

Rousseau, for his part, discovered more disillusionments in his new phase 


of life than he had anticipated. In the first place, he expected Diderot to come 
to the Hermitage regularly, a necessarily one-sided arrangement since Rous 
seau had renounced Paris. 23 In this expectation he was frequently disap 
pointed. In the second place, he found that whenever his benefactress was in 
residence at the big house, La Chevrette, his time was not his own. But 
worse than that was the fact that he had no domestic tranquillity. He had 
brought from Paris not only Therese Levasseur but also her aged mother. 
The old woman played off her daughter against Rousseau, and poor Therese, 
who had too little mind to be able to call what she had her own, was 
completely under her mother s domination. Rousseau discovered, with ex 
asperation and bepuzzlement, that nothing he did won Mme Levasseur s 
loyalty or even her good will. She treated Rousseau with the cunning and 
craftiness of a peasant outwitting the lord of the manor, and Rousseau 
must often have felt like the well-intentioned Nekhlyudov in Tolstoy s A 
Landlord s Morning. Added to this was the fact that Mme Levasseur, during 
the days back in Paris, had negotiated mysteriously with Grimm and Diderot. 
Rousseau now discovered this from Therese, but he could not fathom the 
purpose of this secretive conduct. 

After Rousseau s lively imagination had mulled over the information that 
Grimm and Diderot had been in secret communication with Mme Levasseur, 
he was quite ready to believe that a sinister conspiracy was afoot against 
him. This conclusion probably strengthened his determination to remain 
at the Hermitage through the winter. The grave illness of an old friend, 
Gaufiecourt, called him to Paris on two separate occasions, the first in late 
December 1756 and the second for a two-week period the following January, 
during which time he dined at Mme d Epinay s and lodged at Diderot s. 24 
Indeed it was at this sickbed that Diderot first met Mme d Epinay, a woman 
whose acquaintance he had always refused to make in spite of her close 
friendship with Rousseau and of her having become Grimm s mistress. 25 
In fact, Diderot had attempted to prevent the liaison. Having received a very 
prejudicial view of the lady s character from a former suitor, Diderot had a 
protracted interview with Grimm, during the course of which he claimed 
to have asked his friend impatiently, That is to say that you sincerely be 
lieve that Mme d Epinay is neither false nor a coquette nor a whore? He 
left the interview convinced that his informant was a rascal but still un- 
persuaded that Mme d Epinay was as virtuous as Grimm thought. 26 This 
conversation had taken place about two years before the illness that brought 
all Gaufifecourt s friends, including the hermit from the Hermitage, to his 
bedside. Mme d Epinay had meanwhile become Grimm s mistress, but 


Diderot remained distant. Now, however, a train of circumstances had be 
gun that, as Rousseau saw it, ended by arraying all his friends, Diderot and 
Mme d Epinay no less than Grimm, in a sort of conspiracy against him. 

Rousseau left Gaufifecourt and returned to the Hermitage just before the 
publication of Diderot s Fils naturel It was not long before he came across 
the line only the bad man lives alone/ and accordingly he wrote Diderot 
this particular letter is not extant what in his succeeding letter he 
described as the tenderest and most candid letter I ever wrote in my life, 
complaining, with all the gentleness of friendship, of a very ambiguous 
maxim from which a most injurious application could be made to me. 27 
Diderot s answer was very nonchalant. Moreover, it was bantering in tone. 
But Rousseau was never of the temperament to bear either banter or non 
chalance gladly, and least of all was he in the mood to do so now. The 
emotional crisis into which he was thrown by Diderot s letters at this junc 
ture may be seen clearly in his letters to Mme d Epinay, as well as in her 
efforts to soothe him in reply. 28 

Rousseau, who had made it a matter of principle not to go to Paris and 
who repeatedly declared to Mme d Epinay at this time that he would never 
in his life go there again, 29 suggested that Diderot come to Montmorency to 
see him in order to clear up the point about the solitary man s being evil. 
Diderot wrote: You can very well see, my dear fellow, that because of the 
weather it is not possible to go to find you, whatever the desire and even 
the need that I have of doing so. ... Do you know what you ought to do? 
Come here and stay a couple of days incognito. I would go Saturday to pick 
you up at Saint-Denis and from there we would go to Paris in the same 
cab that brought me. Diderot finally gets around to discussing the line in 
the Fils naturel that had wounded Rousseau, but his reference to it is very 
airy, and compounded with chaffing remarks, especially in regard to Mme 
Levasseur: 1 am glad that my work pleased you and touched you [it cer 
tainly did, and on a very sore spot]. You are not of my opinion regarding 
hermits. Say as much good of them as you please, you yourself will be 
the only one in the world of whom I shall think such good things, and 
even then there would be something to say on that point if one could speak 
to you without angering you. A woman eighty years old! . . . Adieu, citizen! 
And yet, a hermit is a very singular citizen. 30 It will be noticed that Diderot 
by no means claims that the offending line to which Rousseau took ex 
ception had been unintentional or inadvertent 

Rousseau said of this letter that it had pierced his soul. 81 His reply is 
not extant, but one can be sure that it made no attempt to disguise his 


feelings, and it very evidently was successful in annoying its recipient. What 
soever pain my letter gave you, 5 wrote Diderot, 1 do not repent of having 
written it: you were too pleased with your reply. Rousseau having refused 
to come to Paris, Diderot announced, not very good-hurnoredly, his in 
tention of going to Montmorency. Very well, then, Saturday morning I 
leave for the Hermitage, whatever the weather. I shall go on foot. My 
engagements have not permitted me to go sooner, my fortune does not 
permit me to go there any other way. . . . This letter, too, made much ado 
about Mme Levasseur, ending, Live, my friend, live, and do not fear lest she 
die of hunger. 32 

The letter so infuriated Rousseau he told Diderot that it was abominable 
that he wrote to Mme d Epinay that he now devoutly hoped that Diderot 
would not come. But I ought to be reassured [that he won t]. He has 
promised that he will 33 This remark is in allusion to the many times, 
according to Rousseau, that Diderot made appointments and then failed to 
keep them. This time, however, it was Mme d Epinay who kept the friends 
from meeting by sending word that Rousseau would come to Paris instead. 
When he did not appear, Diderot wrote a third letter which is bright 
with his usual conviction of having done no wrong: 

Once for all, ask yourself: Who took part in looking after my health when I was 
sick? Who supported me when I was attacked? Who was it who took an eager 
interest in my glory? Who rejoiced over my successes? Reply sincerely, and recog 
nize those who love you. . . . Oh, Rousseau! you are becoming spiteful, unjust, 
cruel, ferocious, and I weep with sorrow. A nasty quarrel with a man whom I 
never esteemed and loved as I have you, has caused me affliction and insomnia [evi 
dently a reference to Landois]. Guess, then, what pain you are causing me. . . . 
Indicate when you wish it, and I shall hasten to you; but I shall wait until you do. 34 

Rousseau s reply, a few days later, showed how far the mutual misunder 
standing had carried. Had you intended to irritate me in all this business, 
he wrote, what could you have done more? He admitted that he had got 
Mme d Epinay to prevent Diderot s coming to the Hermitage: they would 
only have quarreled. Besides, you wanted to come on foot; you risked 
making yourself sick, and perhaps you would not have been too sorry had 
you done so. I did not have the courage to incur all the perils of such an 
interview.* Each accused the other of self-righteousness. You constantly 
appear to be so proud of your conduct in this affair/ wrote Rousseau, and 
then he cried out, Diderot! Diderot! I see it with bitter grief: living unin 
terruptedly in the company of spiteful men, you are learning to resemble 


them* Your good heart is being corrupted by their society, and you are forcing 
mine, by insensible degrees, to detach itself from you. 35 

It was a pity that Montmorency was not a good deal farther from Paris. 
Distance made communication difficult but not impossible, just when 
mutual distrust was doing the same. As it was, Rousseau was near enough 
Paris for him to expect to see his friends constantly at the Hermitage. By 
his reluctance to set foot in the city he forced his friends into a one-sided 
intercourse whereby they paid the charges both in transportation and time. 36 
And this resulted, in the case of a man like Diderot, never one to be very 
punctilious about his appointments, in broken promises and unfulfilled 
engagements. In Diderot s defense it might be said that he was an unusually 
busy man, occupied not only with his editorial duties but also with Rouelle s 
chemistry lectures and, just at this time, with his play and the complications 
that it brought in its train. Personal contact was difficult, correspondence 
generated as much misunderstanding as it did understanding indeed, 
where mutual confidence was lacking, it generated more - and, to crown all, 
Diderot acted, although probably with the very best of intentions, with a 
singular lack of tact. One has the right to ask Diderot, as Rousseau did, 
what precisely were his motives in harping upon the fate of Mme Levasseur, 
and what precisely did he mean by so publicly and so gratuitously remarking 
that only the evil man lives alone. Candor must reply that, at least so far 
as documents now extant reveal, Diderot never quite justified himself satis 
factorily upon cither count. 


How To Write a Play: Example and Precept 

THE impulse to write plays had come rather sud 
denly upon Diderot in his early forties. He wrote 

two during this period and accompanied each of them with elaborate essays 
upon all aspects of the theater, so that, taken together, his views could 
scarcely be ignored, however much they might be disparaged. The first 
to be published was the Fils naturel ( The Natural Son, or Virtue Put to 
the Test. A Comedy in Five Acts and in Prose. With the True History of 
the Piece ). The True History of the Piece/ to use Diderot s fiction, is 
better known as the Entretiens sur le Fils naturel ( Conversations regarding 
the Fils naturel ) and consists of three dialogues with Dorval, the hero of 
the play, in which numerous aspects of acting and dramatic composition 
were discussed. Four editions of the Fils naturel appeared in the year of its 
publication (1757) ,* and in 1758 there followed the Pere de famille ( The 
Father of the Family ), to which was attached the substantial Discours sur 
la poesie dramatique ( Discourse on Dramatic Poetry ). Though neither 
play was produced by the Comedie-Frangaise before it was published the 
Pere de famille had its premiere there in 1761 and the Fils naturel its 
premiere (which was also its derniere) in 1771 the public nevertheless 
became very aware of Diderot as a playwright, whether because of the 
intrinsic merit of his ideas or the unflagging efforts of his cabal. 

Inasmuch as everyone in Paris who was interested in the theater knew 
that Diderot was the author of the Fils naturel, it might at first seem odd that 
his name did not appear on the tide page. No doubt it was some rather 
dour remarks, especially those in Act III, regarding heaven and the ways of 
its providence, that prevented the work from being published under public 
license. Indeed, the fashion in which the play was received by his relatives 
at Langres shows that it had a tendentiousness that Malesherbes could not 
have dared to endorse by allowing it approbation. On 29 November 1757, 



Diderot wrote to his father, 1 am very sorry to have done something that 
displeases you ... I beg you to believe that it is impossible for me to be 
pleased with myself when you are not. 2 On the very same day he wrote 
to his brother, 1 learn, my dear brother, that my most recent work has greatly 
afflicted you. If that is the case, I d wish I had not written it. ... Tell me 
frankly what displeased you/ 3 But the Abbe refused to be drawn into an 
argument. It was not suitable between brothers, he wrote. Besides, he would 
just bring down on himself what had happened the last time, because the 
same thing is to be found in your book, and, doubtless being unshaken and 
constant in your principles, you would give me the same reply, that I am 
a fanatic, that it is so much the worse for me if I have need of my religion 
in order to be an honest man, that you do not feel this need, that you are 
contented with your own, and that you will never change it. 4 

The Fils naturel was probably offered to the Comedie-Frangaise. 5 If so, 
it must have been a severe disappointment to Diderot that it was rejected. 
He had to content himself with printing in the list of the dramatis personae 
the names of the Comedie-Frangaise actors whom he deemed suitable for 
the various roles. This was an unusual procedure, a little ridiculous, a little 

The publication of the Fils naturel occasioned an uproar. In part, this was 
simply the result of the collision between people who like experimentation 
in the arts and people who detest it. The Fils naturel was sufficiently novel 
in techniques of staging and acting as well as new emphases in character 
analysis and intellectual content to make it controversial. This was not 
because the Fils naturel was the first of its kind to exemplify these new 
ideas in the theater. 6 It was tearful comedy, but so was the theater of 
Nivelle de la Chaussee, whose plays, scornfully dubbed comedie larmoyante , 
had preceded Diderot s by a good fifteen years. Similarly, it was not the first 
to be written in prose; Landois Sylvie (1742) was not in verse. Moreover, 
Sylvie and Mme de Graffigny s Cenie (1750) had both presented seriously 
and respectfully the virtues and vicissitudes of persons of ordinary social 
rank, thus deviating from the conventions of the classic French theater. 
Diderot was, therefore, not so much the first practitioner of what he called the 
genre serieux as its greatest theoretician. 7 And as such he was cried up and 
cried down by those who welcome, and those who abominate, the sacrosanct 
old s being jostled by the irreverent new. 

The plays of Diderot were in sober fact revolutionary, not merely in an 
aesthetic sense but also in a political one. The motivations, the values, the 
morality, the self-evident truths set forth in the Fils naturel and the Pert 


de famille were those of a new social class just beginning to feel its own 
power and to respect its own intuitions. There was nothing, to be sure, so 
revolutionary in Diderot s plays as there was in The Marriage of Figaro, 
where Beaumarchais has Figaro say of his master, What did you do to 
obtain all these benefits ? and then has him answer his own question by 
replying, You gave yourself the trouble to be born/ The political and social 
implications of the new outlook on playwriting, as revealed in Diderot s 
pieces, were as yet more obscure than plain, but they were there; and it is 
impossible to say anything more cogent about Diderot s plays than to repeat 
what Alexis de Tocqueville wrote in Democracy in America. If you would 
judge beforehand, he remarked, of the literature of a people which is 
lapsing into democracy, study its dramatic productions. . . . The tastes and 
propensities natural to democratic nations, in respect to literature, will there 
fore first be discernible in the drama, and it may be foreseen that they will 
break out there with vehemence. 8 

In France they did break out with vehemence there. Diderot s notions 
regarding the theater would no doubt have aroused controversy in any 
event because of the technical innovations they propounded, but the po 
litical implications of the plays as yet dim and obscure were strangely 
disturbing or exhilarating to readers. Moreover, Diderot s views became the 
official dogma of an energetic and assertive coterie, resolved to make its 
judgments prevail. Mme d Epinay, probably motivated by the desire to 
put Diderot under obligation to her, claimed to have disposed of more than 
three hundred copies of the Fils naturel within two days of its publication, 
a rather large number, which a later editor prudently divided by three. 9 
Grimm told the subscribers to his news letter what to think of the new work 
in an ecstatic fashion that suggests his judgment was somewhat biased. The 
Fils naturel was a work of genius. ... [a] beautiful and sublime work : 
Diderot, if he kept on in this way, was destined to become the absolute 
master of the French theater. However unfamiliar may be the sort of comedy 
in the Fils naturel, ou les Epreuves de la vertu; however new may be the 
poetics contained in the three Conversations that accompany this play, 
the enthusiasm of the first few days has been general. All the wits admired 
this work, all the tenderhearted and sensitive souls honored it with their 
tears. Envy and stupidity have not dared to raise their voices, and the public 
has emerged from this bit of reading better and more enlightened than it 
was. 10 Even the hostile Annie Litteraire, still edited by the formidable 
Freron, cheerfully though belatedly admitted with the usual adversative 
but, the usual sting in its tail that the Fils naturel had caused a stir. 1 


cannot express with what warmth the public received this comedy . . . Let 
it suffice for you to know that this drama was for some time the subject 
of all the reading, of all the conversations, and of almost all the praise of 
Paris. Nothing is said of it today. ll 

Critics of Diderot contended that the success of the Fils naturel was 
achieved by the art of puffery. This was the claim of the Encyclopedists most 
dangerous antagonist, Charles Palissot. In a pamphlet entitled Little Letters 
on Great Philosophers, he focused his attention for some forty pages on the 
Fils naturel. Hitch yourselves to the chariot of the new Philosophy, he 
advised obscure authors, . . . make passers-by confess that the Fils naturel 
is a masterpiece, a marvel, a discovery more precious to the world of letters 
than that of America to Europe; and there you are, celebrated, immortal, 
and perhaps some day members of the Academy. 12 Privately many must 
have felt what the poet and dramatist Colle confided to his journal: that the 
Encyclopedists ought to let themselves be praised by others, and not give 
themselves the trouble of taking care of it themselves, as they do every 
minute. 13 

Just at the time that pamphleteers and editors were preparing to attack 
the Fils naturel, Malesherbes used his authority to protect it. So titanic was 
the struggle against the dead weight of all the elements of society opposed 
to change and hostile to reform that Malesherbes often tended to throw 
the weight of his authority on the side of the philosophes in order to equalize 
the contest. For instance, in 1756 he had written to the man appointed to be 
censor of Freron s Annee Litteraire and, after remarking that the authors 
of the Encyclopedic were quite justified in their annoyance at one of Freron s 
quotations in which the Encyclopedic was referred to as scandalous and the 
author of one of its articles as seditious, he inquired how it was that the 
censor had let it pass. 14 The censor, Trublet, replied with some animation: 
It is true that Freron has frequently desired to attack the Encyclopedic 
and its editors in his pages, because, he says, they have often attacked him 
in theirs. I have never allowed these attacks to pass. One day I gave the 
proof of this to M. d Alembert, by letting him read what I had blue-penciled 
in some of the proofs. He appeared to be grateful for this consideration. Since 
then Freron has often returned to the charge, and I to my blue-pencilings. 
Never have I allowed any extract from any work expressly written against the 
Encyclopedic! 15 

Malesherbes policy regarding the Fils naturel is revealed in the censor s 
report about the manuscript of a mild little pamphlet published in 1757. 
Its title, translated, was The Legitimatized Bastard, or the Triumph of Tear- 


ful Comedy, with an Examination of the Fils naturel The author was a 
dull dog, and appears to have used up all his wit in the tide. But perhaps 
his pamphlet, which was principally interested in showing that the tech 
niques of tearful comedy had been used by the ancients, was no sharper 
than it was because censorship had toned it down. In truth, wrote its 
censor, a man named Gaillard, in his report to Malesherbes, there is nothing 
bitter in this criticism. It is even tempered by strong praise, and M. Diderot 
cannot complain of it without being unjust; but as you have had the kind 
ness to inform me of the reasons that make you desire that his work not be 
discredited, I thought that I should inform you of this part of the manuscript 
before approving it. . . . 17 

As far as hostile reviews of the Fils naturel were concerned, Diderot had 
most to fear from Freron. At this juncture Malesherbes let it be known that 
he hoped that Freron and Diderot would become reconciled. Upon receiving 
this intelligence, Freron stopped the presses sixteen pages of an article on 
the Fils naturel had already been printed and wrote Malesherbes a letter. 18 
He suspected a trap and was full of distrust, not least because he knew that 
about 1754 Diderot and D Alembert, learning that Frederick II had authorized 
the election of Freron to the Prussian Academy, had written to the presi 
dent of the Academy that they would resign their membership if Freron 
was elected. 19 Freron now explained to Malesherbes the reasons for his 
reluctance to agree to a reconciliation: He is at the head of a numerous 
society that spreads and multiplies day by day by reason of its intrigues. 
He would ceaselessly beseech me to deal gently with his friends, his as 
sociates, his admirers. I would be able to speak neither of the Encyclopedic 
nor of any Encyclopedist. ... 

Permit me to observe to you further, Monsieur, that it is rather peculiar 
that the moment chosen for reconciling us, M. Diderot and me, is that in 
which he has just given a work to the public. One does not need to be very 
farsighted to see that M. Diderot is aiming at the French Academy, and 
that those who wish him well apprehend, quite rightly, that I will demon 
strate (as I believe I have done) that his Fils naturel the only work he 
has written in the Academy s line, is a detestable play. 20 

It is not surprising that Diderot should, at some time, experiment with 
writing plays. As mentioned earlier, he thought for some time, when he 
was a youngster, of being an actor; he closely studied plays and acting; he 
devoted several of the best pages of Les Bijoux indiscrets to a searching 
criticism of the theater; 21 and he wrote some sort of play, now lost, on the 
basis of which the Abbe Desf ontaines is reported to have declared that Diderot 


had a great talent for dramatic composition. There can therefore be no doubt 
that potentially Diderot was deeply interested in playwriting. If the ques 
tion is posed why Diderot chose this particular and very busy moment in 
which to make lengthy and weighty experiments in a field of letters com 
paratively new to him, Freron s theory that Diderot was aiming at the 
French Academy seems altogether likely. Why not? Diderot was short 
on memberships in academies. Moreover, D Alembert was now a member, 
making the imbalance of official honors possessed by him as compared with 
Diderot more apparent than ever, while at the same time putting him into 
a favorable position to work among his new colleagues for Diderot s ac 
ceptance. Both enemy and friend hinted at the time that Diderot s object 
was to make himself eligible for membership in the Academy. 22 We may 
even conjecture that the publishers of the Encyclopedic hoped that their 
chief editor would be able to achieve such signal recognition. At all events, 
Diderot seems to have taken time from the Encyclopedic to work on the 
Fils naturel and the Pere de jamille, if the very scanty number of his con 
tributions to Volume VII (published in October 1757) is evidence. 

Diderot made his first play more difficult to criticize by pretending that 
the events of its plot had actually occurred. 23 Moreover, from the point of 
view of the theory of playwriting, this suggested that the function of the 
theater is to hold a mirror up to nature. But it was also a prime device for 
evading criticism, getting around awkward objections, and, in short, of 
trying to eat one s cake and have it too. These are the events that were 
supposed to have occurred: 

It is daybreak, and the austere and virtuous Dorval is revealed ordering 
horses for the purpose of leaving at once, his reason being that he has fallen 
in love with Rosalie, the fiancee of his friend and host, Clairville. Rosalie 
is a motherless girl whose father has long been in the Indies and is now 
on his way back to France to bless Rosalie s nuptials with Clairville. Mean 
while, Rosalie is living in Clairville s house, under the care of his widowed 
sister, Constance. Constance is much upset by the news that Dorval is 
leaving, and makes to him a very thinly veiled declaration of love. That 
which follows must be hard to say for a woman like Constance, say the - 
stage directions parenthetically. At this point Clairville enters and begs 
Dorval to intercede with Rosalie in her fiance s behalf. Something seems 
to have happened to her affections for him and Clairville believes that the 
juxtaposition of Dorval s virtue will easily put everything to rights: Such/ 
says Clairville, is the august prerogative of virtue: it impresses everyone 
who comes near it. 



In the John Alden-Priscilla Mullens interview that follows, Dorval, with 
out acknowledging his love, learns that Rosalie loves him. This redoubles 
his resolve to leave the house at once, but as he is writing some .farewell 
lines to Rosalie he is called out of the room to fly to the defense of Clairvillc, 
who is being attacked by armed assailants. Constance enters the room and 
reads the half-written letter, which she takes to be addressed to herself. At 
one point in this second act Dorval s servant ejaculates, No! it seems as if 
good sense had fled from this house. ... God grant that we catch up with 
it on the road. Several contemporary critics regarded this as the best line 

in the play. . TTT 

From the conversation between Clairville and Dorval that begins Act III, 
it is clear that Dorval has just saved Clairville s life. Constance enters, 
shows the tormented Dorval that she has seen his letter and taken it to 
be meant for her, and then, not seeming able to strike much fire from so 
backward a lover, leaves. Clairville accepts Constance s interpretation of 
the letter and speculates on why Dorval had not confided in his friend. 
Did you fear that my sister, learning the circumstances of your birth . . . ? 
Clairville, replies Dorval, you offend me. I possess a soul too exalted to 
conceive such fears. If Constance were capable of entertaining such a 
prejudice, I dare to say that she would not be worthy of me. Rosalie enters, 
learns from Clairville that Dorval is to marry Constance, swoons, and an 
nounces to Clairville upon reviving that she hates him. There then appears 
a servant of Rosalie s father, who explains that master and man had been 
within sight of the French coast when their vessel was captured by the 
British and Rosalie s father despoiled of his fortune and thrown into prison. 
A former business correspondent secured their release, and Rosalie s father, 
now penniless, is in Paris and about to rejoin his daughter. Dorval receives 
the news of the loss of Rosalie s fortune motionless, his head bowed, with 
a pensive attitude, and his arms crossed (such is usually his ordinary at 
titude). He secretly resolves to take from his own fortune in order to 
restore hers, and as the curtain falls on Act III he is seen writing to his 


In Act IV Dorval attempts to persuade the tenacious Constance that 
he is not good enough for her, and that he is leaving in order to exist far 
from men. This is the point in the play where Constance says that only 
the bad man lives alone, the remark that Rousseau took personally. There 
follows a very edifying conversation, full of eighteenth-century philosophy 
regarding virtue. What, for example, would be the chances of their chil 
dren s being virtuous? Dorval, your daughters will be virtuous and decent, 


your sons noble and proud. All your children will be charming . . . and 
I do not fear that a cruel soul might ever be formed in my womb and 
of your blood! When the virtuous but reluctant Dorval reveals the handicap 
of his illegitimate albeit almost guiltless birth, Constance replies, Birth is 
bestowed upon us, but our virtues we acquire/ 

In the last act Dorval demonstrates his virtue and his forcefulness by 
persuading Rosalie in a long harangue that they could never be happy 
together and that she must accept Clairville. At that moment the father 
of Rosalie arrives, and Dorval recognizes him as his father! This remarkable 
coincidence provides a denouement with a vengeance: Dorval and Rosalie 
suddenly finding themselves half-brother and half-sister, there is scarcely 
any use of their engaging in speculation as to whether their children would 
be virtuous, so Rosalie resolves to live happily ever after with Clairville, 
and Dorval with Constance. The curtain goes down with everyone on 
stage bathed in happy tears, according to eighteenth-century prints of the 
final scene. 

Most of the attention paid to the Fils naturel has appropriately enough 
been devoted to its place in the history of the French drama. But it should 
also be pointed out that the play has great biographical significance, not only 
in respect to what Diderot wrote and when and why, but also in regard 
to its revelation of what Diderot valued and admired. Diderot delights in 
Dorval. To him the hero of his play is a hero indeed. And what a hero! A 
man whose charms are so irresistible that he receives two declarations of 
love in a single day, whose courage and prowess are so great that he saves 
the life of his friend, whose generosity is so ample that he divides his own 
fortune for the sake of his friends, whose virtue and eloquence are so 
overpowering that he can recall one of the ladies to her duty, and whose 
self-abnegation and self-control are so triumphant that he can marry the 
other whom he does not love. Surely Dorval was the Super-Man of the 
salons. His creator wrote of him in the spirit of a boy dreaming preposterous 
and fantastic dreams of glory. It may even be that Diderot saw himself 
in this creation of his imagination. Evidence for this identification may 
be found in the fact that Diderot has Dorval s servant saying to him, Mon 
sieur, you are good, but don t go imagining that you are as good as your 
father. 24 Now, these are almost the identical words that a neighbor at 
Langres used in speaking to Diderot about his real-life father, so that to 
many readers the psychological transference will seem apparent. 

Dorval is one of the first in a long line of somber heroes whose souls are 
touched by Weltschmerz and whose hearts are swollen by feelings almost too 


delicate and subtle for ordinary mortals to feel The unquestionable similarity 
between Dorval and Goethe s Werther and the presumable influence of the 
former in the shaping of the latter was noticed very early. 25 Such a hero, 
although usually divested of his preoccupation with virtue, became standard 
in the course of the Romantic Movement. And from Diderot s description 
of Dorval in the following passage, connoisseurs will have no difficulty in 
recognizing the type. He was melancholy in his conversation and bearing, 
unless he spoke of virtue or experienced the transports it causes to those 
who are strongly enamored of it. Then you would have said that he was 
transfigured. His face became serene. His eyes sparkled and became gentle. 
His voice had an inexpressible charm. His discourse became affecting and 
moving, an interlinking of austere ideas and touching images that held 
the attention in suspense and the soul in raptures. But as in autumn evenings, 
during cloudy and overcast weather one sometimes sees a shaft of light 
escape from a cloud, shine for a moment, and then vanish away in an over 
cast sky, so, too, his animation died away, and he suddenly relapsed into 
silence and melancholy. 26 

The impact on public opinion of the Fils naturel was greatly fortified 
by Diderot s doctrines as expounded in the three supplementary dialogues. 
Within the framework of these imaginary interviews, Diderot propounded 
many new conceptions of the drama, conceptions that he was not the first 
to feel but that he was the first to express, at least in so comprehensive a 
way. 27 And because Diderot was an author singularly endowed with the 
gifts of plausibility and persuasion, his precepts as stated in these conversa 
tions were fully as influential as the example of the play itself. 

Many readers will be surprised to learn that Diderot did not attack the 
unities of time, place, and plot which had become an iron rule of the French 
classic stage. Quite to the contrary, he wrote that The laws of the three 
unities are difficult to observe, but they make sense, and both Le Fils naturel 
and Le Perc de famille conformed to them. 28 The reforms he demanded were 
other. One of them was greater realism. He was emphatic in the Conversa 
tions that stage settings are extremely important and really part of the 
action. As a corollary, he wanted the stage cleared of spectators 29 Moreover, 
he interspersed his dialogue with explicit stage directions had Dorval 
drink a cup of tea and peppered his pages with exclamation points and 
broken-off sentences, in order to give some idea of the emphatic style of 
speech and the semi-inarticulateness of persons who labor under strong 
emotions. 30 This led him, incidentally, to discuss the problem of fitting 
prosody to music, a technical problem of the opera that always fascinated 


him. Thus he called for a reform in operatic composition that anticipated 
the opera of Gluck. 31 And he had much to say of the importance of pan 
tomime and gesture. We talk too much in our dramas; and consequently 
our actors do not sufficiently act. 32 And to enhance the illusion of reality, 
Diderot made his play contemporaneous. The scene was laid at Saint- 
Germain-en-Laye, twelve miles west of Paris, and the time was 1757. All 
this was new. 

The purpose of this greater realism was to clear the way for the second 
of Diderot s desired reforms, the creation of what he called domestic and 
bourgeois tragedy. 33 This showed the very great influence that the con 
temporaneous English theater had upon him, especially George Lillo s melo 
dramatic The London Merchant, or the History of George Barnwell (1731), 
and Edward Moore s almost equally melodramatic The Gamester (1753). 
In the conversations with Dorval, Diderot twice mentioned The London 
Merchant and once The Gamester as models of what he had in mind, and 
the abiding influence of Moore s play on him is symbolized by the fact that 
in 1760 he translated it for the edification of some of his friends. 34 As for 
the matter of domestic and bourgeois tragedy/ Diderot did not regard him 
self as having written in that mode. His plays, he thought, belonged rather 
to what he called in 1757 the serious kind of play (le genre serieux), neither 
the old tragedy nor the old comedy but something new and in between, 
something as new as the Fils naturel and at the same time as old as the 
plays of Terence. 35 By the time he had published his Pere de jamille a year 
later, he was calling this sort of play a drama (drame) . The word drama 
in French has therefore come to have a much more specific and less generic 
meaning than in English. It connotes the particular sort of play written 
along the lines recommended by Diderot. 36 

Obviously bourgeois tragedy is tragedy mirroring the vicissitudes, con 
flicts, and values of the middle class. The temptations to which its characters 
are subject are peculiarly middle-class temptations, such as the peculations 
of the apprentice, George Barnwell. The virtues portrayed in such plays are 
those of an emergent and potentially powerful social class, thus illustrating 
De Tocqueville s remark concerning the drama in nations tending toward 
democracy. To people of the seventeenth century nothing could be more 
deliciously funny than the bare tide Le Bourgeois Gentilhomme, for it 
incongruously associated what they deemed inherently incompatible, the 
bourgeois and the gentilhomme. For devotees of the drame, however, this 
attitude was beginning to seem out-of-date and contrary to philosophy, 
In the drame the middle class is portrayed as having dignity and being 


worthy o respect. Commerce, for example, is no longer considered de 
grading. Clairville, upon being asked what he was going to do in view of 
his reduced fortune, says in the Fils naturel, 1 shall go into commerce. . . . 
[It] is almost the only occupation in which great fortunes are proportionate 
to the effort, the industry, and the dangers that make them respectable. 37 

Along with the creation of domestic and bourgeois tragedy, Diderot 
hoped to aid in creating a whole new repertoire of plays to represent the 
various occupations and the various family relationships: The occupation 
ought now to become the principal object, and the character should be 
only the accessory/ 38 Thus there should be portrayed the man of letters, 
the philosopher, the businessman, the judge, the lawyer, the politician, the 
citizen, the magistrate, the financier, the nobleman, the public administrator. 
Add to that, all the [family] relationships: the family father, the husband, 
the sister, the brothers. 39 Thus Diderot raised to a new level of artistic 
importance both the lives of persons whose family ties were strongly knit, 
as in the traditional manner of middle-class families, and the lives of those 
who worked for their living. 

The third and principal object of Diderot in writing Le Fils naturel and 
in expounding his doctrines was to make the theater an institution for 
teaching morality. The philosophes, in almost everything they thought and 
wrote about, were strongly utilitarian. Things should have a use, a function. 
Carrying this axiom over into the theater, it was not enough for Diderot 
and the philosophes that plays should entertain, they must also impel to 
virtuous action. The usual consensus is that this is asking the theater to 
carry a very heavy extra burden, but Diderot demanded it. He has Constance 
say, Doubtless there are still barbarians; and when will there not be? But 
the time of barbarism is past. The century has become enlightened. Reason 
has become refined, and the books of the nation are filled with its precepts. 
The books that inspire benevolence in men are almost the only ones that 
are read. Such are the lessons with which our theaters resound, and with 
which they cannot resound too often. . . . 40 Diderot also referred jocularly 
to an ideal republic to be set up in the island of Lampedusa. In that ideal 
society, actors would fulfill the function of preachers, so useful should the 
theater be. 41 What, asked Dorval, is the aim of dramatic composition? And 
Diderot replied, I believe it is to inspire among men a love of virtue and 
a horror of vice. 42 

Such were Diderot s ideas on how a play should be written, ideas that 
aroused as much scoffing and scorn as they did enthusiasm and admiration. 


The short-range opposition to these notions should not, however, be allowed 
to obscure the long-range importance of Diderot s ideas. No other part 
of Diderot s writings has given rise to a larger mass of studies and criticisms 
than his plays and his essays concerning dramatic literature, writes a recent 
American critic. 43 And the scholar who is generally regarded as the best author 
ity on the history of the drame began his work with these words: Trench lit 
erature in the eighteenth century saw a new dramatic form being born . . . 
Foreshadowed and prepared by the school of tearful comedy, the drame 
acquired with Diderot a very distinct and clear-cut personality. Thus it is from 
the publication of the Fils naturel (1757) && its rea l existence dates. 44 

Although the play was not produced at Paris until 1771, there were at 
least two performances of it in the provinces in the year of its publication. 
These occurred, probably in a private theater, at Saint-Germain-en-Laye, the 
very locale in which the action of Diderot s play was supposed to have taken 
place. Deleyre wrote to Rousseau that he had gone to the first performance, 
where I wept copiously, although not intending to. 45 But Freron declared 
that there was nobody at the second performance! 4S Whether that be true 
or not, the interest aroused by Diderot s drama is attested by the number 
of editions it had. Between 1757 and 1800 it was published in twenty-five 
French editions, four German and three Russian, twice in Italian and in 
Dutch, and in Danish and English once each. 47 

Much of what Diderot wrote in the Fils naturel and its subsequent dialogues 
lent itself to sarcastic comment. In the Conversations he talked a great 
deal about the forthcoming Pere dc jamillc, praised it in advance, and, con 
trary to his usual custom, brazenly sought a patron for it and that in cold 
print. The person he had in mind was a prince of the blood royal, the 
Duke of Orleans, whose chief passion was his love for the theater. 48 More 
over, Diderot s enemies did not fail to notice that the fiction he used of 
DorvaPs having written the Fils naturel gave him the opportunity, while 
seeming to compliment Dorval, really to praise his own work fulsomely. 49 
And if, in his dialogue with Dorval, he made some objections to this innova 
tion or that, it was transparently done to allow Dorval to make a triumphant 
and unanswerable reply. The author makes some objections against his 
play, wrote Palissot, and the Lord knows how much he "pulls his punches" 
(il fait patte de velours). The so-called Dorval replies in so satisfactory a 
manner that M. Diderot is always obliged to agree with him/ 50 Both Palissot 
and Freron thought it a weakness in Diderot s play that he had to rely upon 
an extraordinary coincidence, a deus ex machina, in order to bring his piece 


to an end, and Palissot spoke cuttingly of this old man tumbled down from 
the clouds. 51 Both critics objected to the philosophical and glacial jargon/ 
and complained that there was no contrast between the personages of the 
play, so that all of them seemed to have been cast in the same mold. It 
is always M, Diderot, a philosopher, a metaphysician, who is speaking 
. . . . 52 There was a disposition among critics, too, to claim that even if 
these new ideas were any good, it was not Diderot who invented them; and 
one pamphleteer gave himself the satisfaction of calling Diderot the Amerigo 
Vespucci of the new kind of play, other persons having been its Columbus. 53 

Diderot s enemies presently began to exult in a discovery they made 
that the Fils naturel was very closely modeled on a comedy entitled 11 Vero 
Amico, written by the celebrated Venetian playwright Carlo Goldoni, 
and first produced in 1750 at Venice. Freron wanted to publish the news 
of this discovery by printing a letter purportedly written by Goldoni in 
complaint of the Fils naturel. This Malesherbes refused to allow. He evi 
dently accepted the proof of plagiarism, for Freron had sent him a copy 
of Goldoni s works, but his reason for refusing to allow Freron to publish 
the supposititious letter was that it would be a falsehood worse than all the 
acts of plagiarism in the world, to give to the public under Goldoni s name 
such a letter if it were not really from him/ 54 Freron had to content him 
self with a very indirect although effective approach. In one issue he pub 
lished a full synopsis of the Fils naturel; then in his next issue, under 
pretense of reviewing Goldoni s comedies generally, he published an equally 
detailed synopsis of // Vero Amico > and in doing so he used, where relevant, 
the identical words of his previous summary, thus creating a haunting echo 
effect that would naturally cause readers to look back to try to find out 
where they had read the same thing before. 65 By this device Freron suggested 
to his readers what Malesherbes did not allow him to say outright. 56 

A collation of Goldoni s // Vero Amico and Diderot s Fils naturel shows 
that the situations, the personages (save for an old miser who appears in 
Goldoni s play and is left out of Diderot s), and a good deal of the dialogue 
are extremely similar up through almost half the play. 5T This might be 
called cultural borrowing on the grand scale. But thereafter the plots diverge. 
Moreover, the spirit of the two plays is different throughout. Goldoni s is 
more a farce than a play *of the serious kind : it attempts to impart no 
morality or philosophy, and it has no special middle-class point of view. 
That Diderot s sins had therefore been much exaggerated by his enemies 
was the comforting conclusion pointed out by the contemporary Journal 
Encydopedique : 


Finally, from a three-act farce (half of which was itself borrowed from Moliere s 
The Miser ) there has emerged a symmetrical piece in five acts, written in a vigor 
ous, grave, elevated, and energetic style, and capable of expressing feeling, with 
out which no style can speak to the heart. Let those who desire to despoil M. Diderot 
of his glory, in order to give it to Goldoni, attempt a similar metamorphosis with 
any one of the sixty plays that the fertile Italian has written. Far from reproaching 
them for their theft, we will congratulate them very sincerely for having had the 
skill to do it. 58 

It is difficult for people in the twentieth century to be quite sure how 
heinously Diderot had transgressed against the ethical code of his con 
temporaries in regard to plagiarism. Even in the seventeenth and eighteenth 
centuries, a scholar in the problems of literary history reminds us, public 
opinion was still indulgent in this regard; it was not until the last century 
that plagiarism was condemned as out-and-out dishonesty. 59 Malesherbes 
seems to have partaken of this attitude when he sharply distinguished be 
tween Diderot s plagiarism and Freron s wanting to print a letter pur 
portedly, but not really, written by Goldpni. In Malesherbes eyes, there was 
patently no comparison in the relative guilt of the two offenses. On the 
other hand, it is obvious that Colle took a very severe view of the matter, 
and it is also clear that Diderot s enemies felt that they now had him at a 
considerable disadvantage, from which one may conclude that plagiarism 
was not entirely overlooked by contemporary opinion nor completely con 
doned. 60 Besides, Diderot himself felt constrained to justify his procedure, 
and in 1758, in his Discours sur la poesie dramatique, he made the best of 
admitting what could not be denied: 1 took possession of it as if it were 
a piece of property belonging to me. Goldoni had not been more scrupulous. 
He laid hold of the Avare without anyone s taking it into his head to find 
that bad; and no one among us has imagined accusing Moliere or Corneille 
of plagiarism for having tacitly borrowed the idea of some play either 
from an Italian author or from the Spanish theater. Diderot denied that 
his play and Goldoni s were similar in kind, that his characters and those 
of Goldoni had the slightest resemblance, that there was a single important 
word in the Fils nature! that had been taken from II Vero Amico. And 
then, becoming quite heated, he asserted that *I really wish that there were 
a dozen such larcenies to reproach me with. I do not know whether the 
Pere de famille has gained anything by belonging entirely to me. 61 

Public opinion eventually began to rally somewhat to Diderot s support, 
as the foregoing quotation from the Journal Ency elope dique shows. The 
Mercure de France for February 1759, in reviewing Diderot s Discours sur 


la poesiff dramatique, spoke very sympathetically regarding his explanation. 
I would never end/ wrote the reviewer, were I to cite all unacknowledged 
translations made from one language to another without anyone s believing 
himself obliged to announce them. This is the first time that the name of 
plagiarism has been given to the use of a foreign idea that has been enriched, 
ennobled, and, above all, applied to a genre that is not that of the original/ 62 

Nevertheless, Diderot s conduct when he later came unexpectedly face 
to face with Goldoni betrayed a bad conscience. Goldoni s feelings had been 
hurt, he tells us in his Memoirs,, not so much by the possibility of plagiarism 
after all, plagiarism is a form of very sincere compliment but by Diderot s 
calling Goldoni s comedies farces! Besides, he thought that Diderot s public 
references to him as Charles Goldoni, instead of M. Goldoni, betrayed both 
irritation and contempt. 1 was sorry to see a man of the greatest merit pre 
disposed against me. I did everything possible to draw near to him . . . 
to convince him that I did not deserve his indignation. Finally, Goldoni 
asked a common friend, an Italian musician named Duni, to take him to 
call upon Diderot. Though obviously embarrassed, M. Diderot had the 
honesty to say that some of my plays had caused him much vexation, I 
had the courage to reply that I had noticed it/ 63 The interview seems to 
have ended politely but inconclusively, and although Goldoni was in Paris 
off and on for many years thereafter, their paths apparently did not cross 

The Fils naturel greatly enhanced Diderot s reputation, but it was a 
source of mortification too. A few days after its publication he had written 
to Jean-Jacques, Whatsoever success my work has had ... I have received 
scarcely anything but embarrassment from it and I expect nothing but 
vexation. 64 In this he was prophetic. For some years he had lived in com 
parative tranquillity, he and the more recent volumes of his Encyclopedic 
having given little leverage to his enemies. But the Fils naturel had given 
them a purchase. Presently other untoward events, directly or indirectly con 
nected with Diderot, were responsible for bringing about the supreme crisis 
in the history of the Encyclopedic. 


Rising Opposition; 

D Alembert s Blunder in Volume VII 


CURING all the time that Diderot and Rousseau 
were inexorably proceeding from misunderstand 
ing to misunderstanding, during the time that Diderot was publishing the 
Fils naturel and was being crowned with laurel leaves by his friends and 
contumely by his foes, France was locked in a struggle with England and 
Prussia that should rightly be regarded as one of the first world wars. It was 
in 1757, the year of the Fils naturel, that the Bridsh court-martialed their 
admiral Byng for letting the French capture Port Mahon and had him shot 
on his own quarterdeck to encourage the others/ wrote Voltaire grimly; 
it was in 1757 that Pitt formed his second ministry and out of disorganization 
fashioned order, and victory out of defeat; and, finally, it was in 1757 that the 
French won a battle at Hastenbeck and suffered a national humiliation at 

Little as Diderot concerned himself with the vicissitudes of the war, 
he and his Encyclopedic nevertheless came under some suspicion because 
of it. Principally this was because Frederick the Great, now a national enemy, 
had singled out Diderot and D Alembert for honors. They were members of 
his Academy, as the tide pages of the successive volumes of the Encyclopedic 
testified, and D Alembert in particular seldom overlooked an opportunity 
in articles he wrote for the Encyclopedic to praise the philosopher King. 
During the Seven Years War anyone who could be called an Encyclopedist 
or a philosophy was by that very token imputed to be a bad citizen, recalled 
Condorcet, because France at that time was the enemy of a philosopher 
king who, justly appreciating merit, had given public testimonials of esteem 
to some of the authors of the Encyclopedic x In addition, the Encyclopedists, 
especially Diderot, were hospitable to ideas from abroad, most of all to 



British ones, and in a time of national emergency this could be represented, 
even in that milder age, as faintly smacking of the subversive. 

The year 1757 began on a somber note in the political history of France, 
for on 5 January Louis XV was attacked in the palace at Versailles by a 
man who, mingling freely and unchallenged among the courtiers, got 
close enough to the King to wound him slightly with a double-bladed 
knife. 2 French opinion was appalled. So was the King, who feared that the 
knife, since the wound it inflicted was so trifling, must be poisoned. Damiens, 
the attacker, was easily disarmed, and in due time impressively and hor 
ribly executed. The King, of course, recovered, but the net result of the 
incident was to suggest that the current freedom of canvassing ideas, limited 
as it was, had somehow unsettled Damiens mind and was in general a 
threat to national security. An alarmed public opinion was ready to accept 
strong measures. In February the syndic of the press and his deputies warned 
the members of their guild neither to print nor to sell anything regarding 
present affairs. 3 On 16 April there was promulgated a Royal Declaration, 
a stupendous pronunciamento that stipulated that All those who shall be 
convicted of writing or of having had written or of printing any writing 
tending to attack religion, to rouse opinion, to impair Our authority, and 
to trouble the order and tranquillity of Our States shall be punished by death. 
With reference to all other writings of whatsoever kind, not falling under 
the description of Article I, it is Our pleasure that, for not having observed 
the formalities prescribed by Our ordinances, authors, printers, booksellers, 
peddlers, and all other persons disseminating such writings among the 
public shall be condemned to the galleys for life, or for a term suiting the 
gravity of the case. 4 

This was scarcely a favorable climate for the dissemination of new ideas. 
Nevertheless, from D Alembert s point of view, the seventh volume of the 
Encyclopedic might be the best yet, if we may believe his letters to Voltaire. 
Without doubt, he added, in a letter written in July, we have some bad 
articles on theology and metaphysics, but, with censors who are theologians, 
and with a license, I defy you to make them better. There are other articles, 
less in the open daylight, where everything is made up for. Time will make 
the distinction between what we have thought and what we have said. 5 
Just as the seventh volume was about to be published, there appeared in 
the October issue of the Mercure de France a formidable attack upon the 
philosophes. For some time there had been a lull in the hail of pamphlets 
that had pelted the Encyclopedists, but this persiflage in the Mercure gave 
the signal and set the style for a new onslaught that was destined to end in 


catastrophe for the Encyclopedic. The article was written by a certain Jacob- 
Nicolas Moreau, a publicist who had currently been writing (in a little 
magazine called the Qbservateur Hollandais) a series o comments upon 
foreign affairs favorable to the policy of the French government and, in 
fact, subsidized by it. 6 Moreau was by no means a prominent man of letters, 
and never became one, but his invention of the word Cacouac to ridicule 
the philosophes was one of the palpable hits of the eighteenth century. He 
published his attack in the form of a Due Warning printed in the Mercure. 
These Cacouacs, recently discovered and hitherto unsuspected enemies of 
the public, were strange and loathsome creatures, Savages fiercer and more 
redoubtable than the Caribs ever were. . . . Their weapons consist solely 
of a poison hidden under their tongues* As they are no less cowardly than 
malevolent, they make a frontal attack only upon those from whom they 
believe they have nothing to fear. Most frequently they cast their poison 
from behind. . . . Their whole substance is nothing but venom and cor 
ruption. The source of it is inexhaustible and is always flowing. 7 

Just as the public was becoming Cacouac-conscious in this autumn of 
1757, Volume VII was published. 8 Many of its important articles were 
unexceptionable. Among these were Geometry by D Alembert, and Geog 
raphy by the King s Geographer (Robert de Vaugondy), and those pre 
senting the most recent developments in technology, such as the long and 
detailed articles on Iron-works (Forges, Grosses-) or Stoves (Fourneau). 
But, as always with the Encyclopedic, its articles reflected a desire for im 
provement and a willingness to experiment with change. Quesnay, in his 
article on Grain/ wanted free trade in that commodity. Turgot, who was 
already enjoying a high reputation as a magistrate, wrote the article Fair 
(Foire), and concluded that the great merchant fairs are never as useful 
as the restraint of trade that they entail is harmful; and that far from their 
constituting the proof of the flourishing state of commerce, they can exist, 
on the contrary, only in those states where commerce is hindered, over 
burdened with taxes, and consequently indifferently great. 9 And, as always, 
the Encyclopedic sighed for a state of affairs wherein thought would be 
freer, tolerance more broad. Thus the Abbe Morellet dared to praise religious 
freedom in the United Provinces. The Dutch magistrates have finally 
learned,* he was allowed to write, in an article that he tells us was heavily 
censored, that for the sake of peace they should abstain from participating 
in such disputes; allow theologians to speak and write as they please; let 
them confer if they want to, and come to decisions, if that pleases them; 
and especially persecute no one.* 10 


In a very important and influential article on Endowments (Fondation), 
Turgot examined, as he said, the utility of [perpetual] endowments in 
general in regard to the public welfare, or, rather ... the disadvantages of 
them. Even endowments made for the best of motives to say nothing 
of those set up out of vanity tend to outlive their usefulness, or to encour 
age mendicancy instead of discouraging it, or to be abusively administered. 
Salutary change could be brought about, he wrote, either by improved laws 
applying to all of society or by temporary endowments subject to discon 
tinuation when the need was past, such as was then being done by associations 
of citizens in various places in England, Scotland, and Ireland for the purpose 
of increasing employment. What has occurred in England can take place 
in France: for, whatsoever one may say, the English do not have the ex 
clusive right of being citizens a daring thing to publish in an absolute 
monarchy in the midst of a war with England. In this article Turgot used 
time and again the stirring word citizen, and said that employments and 
offices of all kinds should become the recompense of merit. What the state 
owes to each of its members is the destruction of obstacles that would hinder 
them in their industry, or that would disturb them in the enjoyment of 
the products that are the recompense of it. It was not for nothing that 
Turgot was a close friend of Gournay, the man who invented the formula 
of laissez-faire et laissez-passer. Noteworthy in this article is the sober but 
earnest appeal to public opinion, and the reference to public utility as the 
criterion of decision. Public utility is the supreme law/ wrote Turgot in 
this article a principal tenet of faith of the Encyclopedists in regard to 
all social, economic, and political policy, and one capable of cutting through 
all the political obscurantisms of the ancien regime. 1 * 

This article was published without attribution to Turgot, so that Diderot, 
as editor, accepted the further responsibility of seeming to be its author. If 
to praise the English was to be unpatriotic, Diderot took the burden of it. 
If it was subversive to assume that the state owes something to its members, 
if it was disloyal to speak of the state rather than the king, Diderot shouldered 
that onus, too. 

The Encyclopedist lack of interest in political and diplomatic history 
of the conventional sort is exemplified by the brevity of the article devoted 
to Trance/ This article, written by De Jaucourt, disposes of the subject 
in only nine hundred words, and many of these are taken up, not by an 
account of French history, but by deploring France s uneven distribution 
of wealth (comparing it to Rome at the time of the fall of the Republic ), 
the depopulation of the provinces, the overimportance of Paris, and the 


poverty of the cultivators of the soil. And De Jaucourt, using the technique 
of cross reference, declares that causes and remedies of these evils are not 
hard to find: See the articles "Tax" "Tolerance" &c. 12 But if the Ency 
clopedic was not interested in political history, nevertheless it had a political 
point of view, and in the article on Government De Jaucourt wrote, The 
people s greatest good is its liberty. Liberty is to the corporate body of the 
state what health is to each individual. Without health, man cannot savor 
pleasure. Without liberty, happiness is banished from states. 13 

In theological and religious matters, the Encyclopedic continued its policy 
of pinpricks and knowing winks. The article on Grace, for example, which 
may have been written by Diderot, commented somewhat obtrusively upon 
the futility of a subject that had not seemed so to Saint Augustine. Besides, 
wrote this unknown author, so much has been written upon this subject 
without in any way illuminating it that we apprehend laboring quite as use 
lessly. The principal works of the theologians of the several parties may be 
read concerning these matters. The discussions, very frequently minute and 
futile, to which they have given rise, do not deserve a place in a philosophical 
work, however encyclopedic it may be. 14 Nor did the Encyclopedists forget 
to twit the Jesuits, as when Voltaire began his brief but ostentatiously learned 
article on Fornication : The Dictionnaire dc Trevoux says that it [fornica 
tion] is a term in theology ! 15 

Regarding the history of religions, the Encyclopedic sought as usual to find 
a rational explanation for the origin of what it regarded as irrational practices. 
Thus Diderot wrote of the Roman sacrifice of milch cows heavy with calf 
(in Fordicides } , his explanation of this pagan phenomenon being that Numa 
had instituted the practice to alleviate some calamity, such as a lack of forage, 
and that the sacrifice had continued long after the condition necessitating it 
had passed away. From which I conclude, he wrote gravely, that one cannot 
be too circumspect when commanding something in the name of the gods. 16 
This method of studying primitive religious practices, not unlike Sir James 
Frazer s in The Golden Bough, was best displayed in Volume VII in a re 
markable article on the Parsees (Guebres). Starting with the tenets of Parsee 
faith, the author, Nicolas-Antoine Boulanger, broadened out to give a theory 
of the origin of myths and of their role in all religions. 17 It was a way of sug 
gesting, of course, the genesis of Genesis. 

Diderot s contributions to Volume VII were not numerous, but a reader 
finds the now familiar touches : the graceful image *I regard these fragments 
of philosophy that time has allowed to come down to us as though they were 
planks that the wind casts up on our shores after a shipwreck, allowing us 


sometimes to judge o the size of the vessel ; the subjective O sweet illusion 
of poetry! You are no less charming to me than truth itself. May you touch 
me and please me until my last moments ; 18 and the personal, this time a 
portrait of himself in reverse in his article on Formalists, In his distaste for 
the pettifoggers of good form, Diderot showed himself par excellence the 
man who always hated to wear a wig. 19 

Famous among the articles of the Encyclopedic, and perhaps the most fate 
ful of them all, was D Alembert s ill-starred contribution on Geneva. Usually 
the Encyclopedic had almost nothing to say under the heading of sovereign 
states three-fifths of a column allotted to England, a column to Genoa, a 
little over a column to Spain, seventeen lines to Denmark but to Geneva 
D Alembert devoted four double-columned pages. His knowledge was first 
hand, acquired during his visit to Voltaire in the summer of 1756. Gossip had 
it, after the storm broke, that Voltaire had put D Alembert up to writing the 
article and that Voltaire might even have written part of it himself, as 
Rousseau believed, the purpose being to insert in it proposals for allowing 
the production of plays in Geneva. 20 In that Calvinist city-state the theater 
was looked upon with as much favor as it was at about the same time by, 
say, Cotton Mather, Jonathan Edwards, or the divines of Salem, Providence, 
and New Haven. To this subject D Alembert devoted a whole column : Tlays 
are not allowed at Geneva, not because stage spectacles are there disapproved 
of in themselves, but because, it is said, of the fear of the taste for display, dis 
sipation, and libertinage that companies of actors communicate to the youth. 
Nevertheless, would it not be possible to remedy this drawback by having 
severe and strictly executed laws governing the conduct of actors? 21 

On the whole, D Alembert had evidently intended to be very complimentary 
to Geneva, especially because, like Tacitus writing about the Germans, he 
wished to improve his own countrymen by calling their attention to more 
virtuous foreigners. Thus he pointed out that the Genevese did not allow 
prisoners to be put on the rack, save in very special circumstances, and he 
spoke with great approval perhaps he had imbibed this doctrine, too, from 
Voltaire, who had long believed in it of their practice of burying the dead 
in a cemetery outside the city. 22 He also approved of the rigorous examination 
of the theology and morals of a minister before he was ordained and evidently 
before he was assigned to a pastorate, remarking that it is to be wished that 
most of our Catholic churches would follow their example. But D Alembert 
was a prim and schoolmasterish man, and he could not forbear remarking 
on matters that the Genevese could scarcely be blamed for thinking were 
none of his business. Thus he reproved them for retaining a certain part of 


their heraldic coat of arms. He told them that they should obliterate a certain 
inscription upon their city hall. Speaking of their divine services, he remarked 
that the singing is in rather bad taste and the French verses that are sung arc 
worse yet. It is to be hoped that Geneva will reform itself upon these two 
points. He observed that Calvin was as enlightened a theologian as a heretic 
can be/ a remark which probably displeased the Calvinists as being too 
grudging and the Sorbonne as being too generous. 23 In short, it is likely that 
a Genevese would have read D Alembert s article with more irritation than 
gratification, and it is hard not to look upon it as a monument of tactless 
ness. From whatever point of view this article is regarded, one is tempted to 
say, in the vernacular of American sports, that D Alembert led with his chin. 

Nor was this the sum total of its offenses. The article Geneva almost occa 
sioned an official protest from the Genevese government to the French gov 
ernment because of the remarks D Alembert made about the condition of 
religious belief in that sovereign city-state: Several [of the clergy] no longer 
believe in the divinity of Jesus Christ. . . . several of the pastors of Geneva 
have no other religion than a perfect Socinianism, rejecting everything hav 
ing to do with mysteries, and conceiving that the fundamental principle of a 
true religion is to propose for belief nothing shocking to reason. 24 

Soon after the publication of Volume VII, Grimm was calling this article 
a blunder, and reporting that it was creating a great stir at Paris. 25 It created 
an even greater one at Geneva, where the corps of Calvinist ministers were 
highly embarrassed by this public allegation that they were deists or, at the 
least, a variety of eighteenth-century Unitarian. To call a person a Socinian 
when he was officially committed to a belief in the Trinity and in revelation 
was to use fighting words, and it is not surprising that the ministers sought 
public amends. The Council of Geneva meeting on 9 December tried to 
find whether there be not some measures to take in order to have this article 
changed or suppressed. 26 It hesitated to make a formal complaint to the 
French government only for fear that the French would make some disagree 
able demand in return. As late as 15 January 1758, the possibility that an official 
complaint would be lodged with the French government was not entirely 
past. 27 Meanwhile, the Company of Pastors appointed a Committee of Nine 
to draw up a reply. The Declaration they formulated was sent to all the 
editors of Europe and Freron printed it in his Annie Litterairc in February 
of that year. 28 

The secretary of this committee was a Genevese layman, Dr. Theodore 
Tronchin, the famous physician who in 1756 had made himself one of the 
best-known men in France by his successful inoculation against smallpox 


of the two children of the Duke of Orl&ns. 29 At that time he had become 
acquainted with Diderot, and in due course he became a contributor to the 
Encyclopedic, his article being, appropriately enough, the one on Inocula 
tion. 30 One of his first duties as secretary of the Committee of Nine was to 
write to D Alembert and Diderot to secure a retraction. D Alembert s reply 
gave him no satisfaction at all 31 From Diderot he received a letter that illu 
mines the relations between the two editors and implies that Diderot had 
disapproved of his colleague s action. 32 

This letter, evidently composed with great care, if we may judge from the 
profusion of conditional tenses, suggests a divergence in editorial policy be 
tween the two men. Although Diderot did not explicitly claim that he tried 
to prevent the publication of the article, he did say he had had no share in 
it and he certainly implied that he would not have published it had the de 
cision depended upon him. Did he really advise against its publication, or 
was he trying to deceive Tronchin into believing that he had? The latter 
alternative seems the less likely, for Diderot was not a pusillanimous man. 
An attempt on his part to cultivate Tronchin s good will at D Alembert s ex 
pense is not in character. Besides, Diderot must have realized how much it 
was to the interest of the Encyclopedic to preserve a united front in this 
crisis. Indeed, one may well ask why he did not assume equal responsibility 
as far as Tronchin was concerned, whether or not this corresponded to the 
reality of the case, and try to brave it out. On the contrary, he steadfastly 
claimed not to be responsible, although offering to take the blame publicly on 
himself. Finally, if it be remembered that D Alembert never alleged, either 
in his letter to Tronchin or in his correspondence with Voltaire, that Diderot 
had approved of the article on Geneva before or after its publication, the 
inference that Diderot disapproved of publishing the article seems strong. 
Had D Alembert been able to divide responsibility with Diderot, it would 
have been manifestly to his advantage to do so. 

It is evident that Tronchin interpreted the situation as meaning that 
Diderot had not favored publication. Writing to a Swiss colleague a few 
days after receiving Diderot s letter, Tronchin remarked that His co-editor, 
Diderot, who is, of all the men I know, the most humane, would never have 
done what D Alembert did. And Tronchin continued (but unfortunately 
without citing sources), Opinion was unanimous against the article, before 
it was printed. Therefore M. d Alembert cannot say that he did not foresee 
its effect. He alone held out against them all. Whatsoever reasons were used 
to combat his obstinacy, he did not wish to give in, [and] the article was 
printed. 33 


What, after all, can explain Diderot s willingness to allow Tronchin to in 
fer that he had not approved of D Alembcrt s article? Could Diderot have 
been motivated by the desire to prevent Voltaire from ever again using the 
Encyclopedic to serve his own private purposes? As Grimm remarked in the 
Correspondence litteraire and his and Diderot s ideas did not usually 
diverge very far *I cannot express how out of place this whole article was 
in the Encyclopedic, in which the city of Geneva ought to occupy the space 
of three or four lines, and not entire columns for the purpose of telling us 
what it should or should not do a subject absolutely foreign to the arts and 
sciences that constitute the subject of this dictionary. 3 * Diderot s usual policy 
of holding Voltaire at arm s length made itself very conspicuous at this junc 
ture. Voltaire repeatedly sent regards to Diderot in letters to D Alembert and 
even in a letter to the publisher Briasson. 35 Diderot did not reciprocate. Then 
Voltaire, in this crisis, wrote directly several times, but to his extreme annoy 
ance, Diderot neglected to reply. 36 Perhaps Diderot thought it outrageous of 
Voltaire and D Alembert, too to jeopardize the fate of the whole En 
cyclopedic so that Voltaire might see a play in Geneva. It is therefore con 
ceivable that Diderot welcomed the opportunity of a showdown with D Alem 
bert, once the latter had precipitated the issue of Voltaire s influence in so 
clean-cut a fashion. The distrust of D Alembert that Diderot had already 
evinced in the letter written in 1755 makes this explanation even more likely. 37 
Unquestionably the Encyclopedic was made vulnerable by the article on 
Geneva. It seemed presumptuous and arrogant in its cocksureness regarding 
matters both temporal and spiritual. It tended to reflect on the judgment of 
the editors. And just as it came close to involving the Ministry of Foreign 
Affairs, so, too, it almost precipitated an investigation by the Parlement of 
Paris. It is asserted, wrote D Alembert to Voltaire, reporting this new dan 
ger, that I praise the ministers of Geneva in a fashion prejudicial to the Cath 
olic Church. 38 The enemies of the Encyclopedic were becoming bolder, and 
scarcely anyone missed the significance of the fact that a Jesuit dared to preach 
a sermon at Versailles, in the presence of the King, attacking the Encyclo 
pedic?* The article on Geneva was not the sole cause of the increasing com 
plaints against the work, but it undoubtedly encouraged the accelerating 
tempo of the attack* 

Furthermore, it is probable that D Alembert s ill-favored article on Geneva 
precipitated the crisis regarding censorship that overtook the Encyclopedic 
following the publication of the seventh volume. If the Parlement of Paris 
should investigate the Encyclopedic, as it threatened, then it was inevitable 
that a number of searching questions would be asked as to how offending 



passages had happened to secure approval. Evidently Malesherbes deemed 
it prudent, for his own protection, to ask the questions first. An undated note 
in his almost illegible hand stated that I learned with the greatest surprise 
that articles had been printed that had not been reviewed by any one of the 
three theologian censors . In another notation Malesherbes revealed how this 
had happened. Undated and unsigned but unquestionably m his highly in 
dividual writing, it stated that the agreement of I75 2 was observed for the 
third volume and, at most, for the fourth. Since that time the editors and 
publishers have fallen again into the habit of arbitrarily sending each article 
to the censor in whose province they deemed it to belong. This is what has 
given rise to the complaints occasioned by the seventh volume. 41 Nor did 
the publishers deny that this was what had occurred. Le Breton wrote to 
Malesherbes on 24 December to say that there have not been printed any 
sheets, particularly of the last five volumes of the Encydopedie, without their 
being initialed by one of the censors whom you have assigned to us, but he 
could not claim that everything had been reviewed and passed by one of the 
theologian censors. 42 From this Malesherbes evidently concluded that these 
censors had been negligent, for he drafted a very stiff rebuke to the chief of 
them, commenting on the publication of some articles which it is impossible 

that any one of you three had approved You ought to have complained 

that the present rule was being evaded, and because you have not done so, you 
have shared in the transgression of the authors and printers. 43 Henceforth, 
every single sheet was to be initialed by one of the three theologian censors. 
Malesherbes was fortunate that the breakdown of his previous orders did not 
become public knowledge, and he was quite justified in insisting that the 
rules agreed upon in 1752 should be carried out punctiliously. Nevertheless 
D Alembert, particularly, chose to regard Malesherbes orders as a new en 
croachment and another grievance. 

Hostile pamphlets also plagued D Alembert at this time. One of them 
was Little Letters on Great Philosophers by Palissot whose enmity D Alem 
bert had earned in 1755 when he protested in Rousseau s behalf against Le 
Cercle. Now Palissot, young in years but old in enmity, returned to the at 
tack, an attack which D Alembert believed to have the protection of patrons 
in very high places. In just a few pages Palissot managed to touch a great 
many sore spots. He twitted Diderot and D Alembert for having copied 
Bacon servilely ; ridiculed Diderot s opening words in his Pensees sur I in- 
terpretation de la nature, Young man, take and read ; laughed at the state 
ment that deer attain the age of reason; sneered at Diderot s pamphlet on 
Encaustic ; remarked that the editors formerly praised Rameau; and chided 


them for being so morbidly sensitive to criticism. Palissot accused his enemies 
of monopolizing the term philosopher All these gentlemen call them 
selves Philosophers. Some of them are. He took care to remind the public 
that D Alembert was the beneficiary of a Prussian pension, and he also criti 
cized the D Alembert eulogy of Montesquieu which had appeared as a fore 
word to Volume V: There reigns in it a tone that is revolting. It is not 
so much the expression of public admiration as it is an order to the Nation 
to believe in the merit of this illustrious writer. Most of all, Palissot com 
plained of the philosophes forming a party, of their pronouncing upon repu 
tations, of the ostentatious praise that these gentlemen mete out to one an 
other, of this tone of inspiration on the part of some, of emphasis on the part 
of others, of their intolerance, of their setting up for themselves a literary 
throne, of their saying in effect that No one shall have wit save us and our 
friends. And Palissot hinted that the philosophes were by way of becoming 
a church: At the front of certain philosophical productions one may observe 
a tone of authority and assurance that until now only the pulpit has exer 
cised. 44 

This was quite bad enough, especially after Freron lovingly reviewed it in 
his Annee Litteraire.^ But Moreau s New Memoir to Serve toward the 
History of the Cacouacs was even worse. In this more extensive account of 
the habits and manners of those formidable creatures, the author informed 
the public that the only weapon that the Cacouacs feared was a whistle. 
Whistling put them into disarray and sent them headlong into flight, a 
remark disclosing that in the eighteenth century as in the twentieth, whistling 
is to a Frenchman what booing is to an American today. The author of the 
Memoir* had forgotten his whistle and was consequently captured by the 
Cacouacs. He was disarmed to the strains of Italian music, and then an old 
man came into the room with a book, and said, Young man, take and read. 
The Cacouacs, according to their prisoner, were anarchists; they denied the 
existence of the gods; the only thievery they permitted themselves was that 
of the thoughts of others; they particularly coveted the glory of destroying 1 ; 
they were absolutely indifferent to patriotism, no longer recognizing any other 
fatherland than that of the entire universe; and by common consent they 
accepted lying as a general practice. The captive discovered that the Cacouacs 
were great talkers : their language has something sublime and unintelligible 
in it that inspires respect and arouses admiration. He himself became pro 
ficient in their idiom: I continued to shine. Ideas came to me. But if some 
times they failed me, I had some big words to put in their place, and I no 
ticed that then it was that I was applauded the most vigorously. He was 


initiated into their mysteries by being permitted to peep into their seven sacred 
coffers (the seven volumes o the Encyclopedic). With surprise I observed 
a confused mass of the most heterogeneous materials gold dust mixed 
with iron filings and lead slag, diamonds half-concealed in piles of ashes, 
and the salts of the most salubrious plants mixed up with the most noxious 
poisons/ The prisoner was given a valet, who robbed him while virtuously 
quoting to him his own philosophical principles. This valet, moreover, had 
written a book entitled New Discoveries about Tragedy, or the Art of Com 
posing Very Fine Scenes out of Grimaces. After a number of adventures, 
the captive was able to return to his own country. There he discovered that 
it was later than he thought: the Cacouacs were already there! These danger 
ous and ridiculous Cacouacs ... had been given the name of Philosophes, 
and their works were being printed! 4e 

Americans have a phrase to describe this kind of persiflage a rock in 
every snowball. Diderot seems to have borne it without a flutter of nerves, but 
D Alembert was overawed because he believed it to be officially inspired and 
because he claimed to know that Malesherbes, although desirous of prevent 
ing publication, had received orders from higher up to see that it was not 
suppressed. 47 

At this singularly unpropitious time, D Alembert chose to draw a large 
draft on Malesherbes fund of good will. Freron, as may readily be imagined, 
had unctuously and gleefully digested the New Memoir for his readers, for 
getting none of the most painful parts. 48 But whereas Moreau had not alluded 
to D Alembert by name, Freron inserted in a footnote a reference to one of 
D Alembert s works, thus making the connection unmistakable. It was, in 
fact, as Malesherbes called it, nothing but a subtlety, but nevertheless D Alem 
bert took great umbrage. 49 Malesherbes was sufficiently moved by D Alem 
bert s protest to inquire of Freron by what right he used personalities in at 
tacking his enemies, to which Freron made sturdy and independent reply. 50 
Yet it is evident that Malesherbes, although he wrote to Freron, was never 
theless exasperated by D Alembert s protest. Moreover, Malesherbes was very 
aware of his own delicate position at this particular time, for he wrote to the 
Abbe Morellet, who became the intermediary in the affair, 1 am even more 
sorry to see how the chagrin caused by the pamphlets has blinded him to the 
point of not sensing how indiscreet it is and, I venture to say, unreasonable, 
coolly to demand redress from Freron at the moment when the seventh vol 
ume of the Encyclopedic and especially the article "Geneva" have excited the 
most powerful outcries, and when one cannot defend the work nor take the 
side of the authors without exposing oneself personally to very grave re- 


proaches. 5 51 In this letter and in one to D Alembert, Malesherbes outlined the 
guiding principles of his administration. 52 These were liberal and inspiring 
documents, even though, as Malesherbes predicted and as Morellet tells us 
in his Memoires, D Alembert was very discontented with them. 53 The inci 
dent shows clearly enough that of the two men, the magistrate and the writer, 
it was not the writer who desired freedom of the press. Malesherbes implied 
that what D Alembert wanted was the right to say what he pleased and the 
refusal of the same right to his enemies an analysis very close to the truth. 
His protest to Malesherbes against Freron was so poorly justified and so 
plainly ill-timed that Malesherbes began to suspect an ulterior motive. In 
the draft of his letter to Morellet, Malesherbes wrote (and then scratched 
out) the following sentences: If I knew M. d Alembert less well, I might 
suspect him of seeking to prepare, relative to the public, a pretext for quitting 
the Encyclopedic. But I do not believe him capable of it. 54 

As early as i January 1758 D Alembert claimed to have informed Males 
herbes and the publishers of his decision to give up the Encyclopedic; and 
in his reply of 6 January 1758 to Tronchin, he added a postscript: *I ought to 
add, Monsieur, that reasons of an essential character, having no relation to 
the article "Geneva," oblige me to give up my work on the Encyclopedic 
absolutely and once for all. Thus it seems to me that this work, brought to a 
stop in the middle of its course, no longer merits becoming the subject of the 
complaints of your clergy. 55 It is of great interest to notice that at this writing 
D Alembert evidently took it for granted that his quitting would mean the 
end of the Encyclopedic. Five days later he wrote to Voltaire that he did not 
know whether the Encyclopedic would be continued or not. What is certain 
is that it won t be by me. I have just notified M. de Malesherbes and the 
publishers that they may search for my successor. I am worn out by the in 
sults and vexations of all kinds that this work brings down upon us. 56 

Before receiving the foregoing letter Voltaire heard a rumor that D Alem 
bert was intending to quit and hastened to urge him to stick it out. 57 Then, 
in answering D Alembert s letter, Voltaire again urged him not to resign. 
Do not abandon it. Do not do what your ridiculous enemies want. Do not 
give them this insolent triumph. ... I know that it is shameful that a so 
ciety of superior intelligences, working for the good of the human race, should 
be subject to censors not worthy of reading you; but can you not choose 
reasonable revisers? Cannot M. de Malesherbes aid you in this choice? 58 
But D Alembert, replying to the first adjuration, wrote that In regard to 
the Encyclopedie, when you press me to take it up again, you are ignorant 
of the position we are in and of the fury of the authorities against us. ... 


I don t know what course Diderot will take. I doubt that he will continue 
without me. But I know that if he does, he is preparing for himself trials and 
tribulations for ten years/ 59 

Quite suddenly Voltaire had an abrupt change of heart. Instead of be 
seeching D Alembert to stay on, he now began to insist that everyone con 
nected with the Encyclopedic should quit with him. 60 As long as Voltaire 
had supposed that the author of the memoir about the Cacouacs was a Jesuit 
or inspired by the Jesuits, he was brave. But when he learned from D Alembert 
that these attacks were protected and perhaps inspired by the Court, he be 
gan to be very cautious and, while still lustily blowing the trumpet for a 
charge, hastily beat a retreat. 61 Reversing his earlier and braver sentiments, 
he now wrote that it is absolutely necessary that all those who have worked 
with you should quit with you. Will they be so unworthy of the name of 
philosopher, so cowardly as to abandon you? 62 Frightened himself, Voltaire 
found it a good time for calling other people cowards. 1 have already told 
you/ he wrote to D Alembert on 13 February, that I wrote Diderot more 
than six weeks ago, first to beg him to give you courage regarding the ar 
ticle "Geneva" in case they tried to intimidate you, secondly to say to him 
that he must join himself to you, quit with you, and not take up the work 
again except with you. I repeat to you, it is infamous not to be united as 
brothers in such a situation. I have also written to Diderot to return my letters 
[and my] articles. . . . Henceforth I do not wish to furnish a line to the 
Encyclopedic. Those who will not act like me are cowards, unworthy of the 
name of men of letters. . . . 63 

D Alembert does well to quit, wrote Voltaire to a friend in Paris, and the 
others, by continuing, are acting like cowards. 64 

Throughout this flurry of volubly explaining why one should give up, 
there was one of the protagonists who said nothing. In all this scurry of 
letting go, one man held fast. Diderot simply kept on. No doubt the per 
plexities of the situation were increased by his friends pressure on him. Even 
Rousseau, frightened by the rumors that are going about regarding the 
Encyclopedic and fearing for Diderot s safety, wrote a letter urging him to 
quit if D Alembert did, although it is not known (the letter not being ex 
tant) whether he too called Diderot a coward! 65 In mid-February Diderot 
at last wrote to Voltaire, excusing himself for not having replied earlier, 
and describing his motives for not giving up or finishing in a foreign country, 
as Voltaire had suggested. They were motives which Voltaire grumbled at 
and which D Alembert obviously did not regard as decisive, but nevertheless 
the letter shows a willingness to accept moral responsibilities and honor them 


in the face of adversity that ought to be acknowledged as commendable 
and courageous: 

... To abandon the work is to turn one s back on the breach and do what the 
rascals who persecute us desire. If you but knew with what joy they learned of 
D Alembert s desertion and what maneuvers they undertake to prevent him from 

What Diderot really thought of D Alembert s action is revealed by that 
word desertion. His own attitude, Diderot wrote later in his letter, was not 
inspired by an overwhelming fondness for the Encyclopedic: 

My dear master, I have passed my fortieth year. I am weary of bickering. From 
morning to night I cry Rest! Rest!* and there is scarcely a day when I am not 
tempted to go to live obscurely and die tranquilly in the remotest part of my 

But this was the second movement, written in a minor key, of a battle 
symphony. What was it, then, that Diderot thought should be done? 

That which is suitable for men of courage: Despise our enemies, pursue them, 
and profit, as we have already done, from the imbecility of our censors. ... Is it 
honest to disappoint the expectations of four thousand subscribers, and do we 
have no obligations in respect to the publishers? If D Alembert starts over again 
and we complete the work, won t we be avenged? . . . Someone else might re 
joice over his desertion, seeing gain in it of honor, money, repose. As for me, I 
am disconsolate over it, and I shall neglect nothing to bring him back. Now is 
the moment for me to show him how much I am attached to him, and I shall not 
fail either him or myself. But for God s sake, do not counteract me. I know how 
great is the influence you have over him, and it will be useless for me to prove to 
him that he is wrong if you tell him that he is right. 

Don t be angry any longer, and especially do not ask me any more for [the re 
turn of] your letters; for I would send them back to you and never forget such an 
injury. Your articles I do not have, they are in D Alembert s hands and you well 
know it. 66 

Voltaire did not receive Diderot s letter with very good grace. The trouble 
all arises from M. Diderot s not making from the first the same declaration 
as M. d Alembert. 67 It is a pitiful thing, he wrote a month later, that asso 
ciates of such high merit should be masters neither of their own work nor 
of their thoughts. Accordingly the edifice is built half of marble and half 
of mud/ 68 


much a disappointment to D Alembert as it dedsion to 

"somc Me consideradoa and some support. The justice he asked for 
Zed U he realized, perhaps too late, that henceforth nothing 
mike the Encycloptdie secure from the gravest and most unjust impu- 
t tan the soft of inquisition being prepared to be used against it. 
Th rlre he adopted the wise policy of henceforth lunmng hmse f - 
duLy in this Dictionary to the mathematical part, winch cannot be sub- 
d dtTer to the clamors of false zealots or to the chicanery of a censor, 
and which, besides, is the only part for which he contracted solemn engage- 

^ e :;" G L the disconcerting e*ect of putting D Alembert 
at odds with people whom he assuredly did not want to antagonize -with 
^e cltgy of Geneva, with the Court at Versailles, with the Clement of 
Paris with Diderot, with Malesherbes, and even, most unexpectedly, with 
Rousseau. For Jean-Jacques, nostalgically remembering his childhood m the 
puritan city of his birth, took exception to D Alembert s arguments for aUow- 
Lg theatrical productions in Geneva. The result was a spmted htt k book 
attacking the theater as an immoral and enervating institution and defending 
republican simplicity. Rousseau s La** a D Alembert sur Its spectacles was 
written just at the time of greatest strain and anguish in the relations of 
Rousseau and Diderot, and its publication revealed with dramatic emphasis 
to the jubilant enemies of the Encycloptdie that their foes camp was di 
vided, their united front broken. Thus was added still another to the cata 
logue of woes that the article Geneva brought in its train. 


I Used To Have an Aristarchus . . , 
I Wish To Have Him No Longer 

"TVRECisELY at the time that his friendship with Rous- 
IT seau was slowly going to pieces, Diderot was con 
tinually beset by other distractions and anxieties. As always, there was the 
routine of editing the Encyclopedic, the chronic and Spartan necessity of earn 
ing a livelihood, of paying the rent at the Rue Taranne. Added to this was 
the time spent in creating and defending his controversial experiments 
in playwriting. This was the year in which he had the exhilaration of being 
hailed as a dramatist of genius and the bitterness of being called a plagiarist 
of the very first rank. This was the time when he seems to have cherished 
the intoxicating hope of election to the French Academy, Perhaps it was 
the time, too, when he came to the grim realization that his hopes would 
never be fulfilled. This was the year in which he was held up to scorn as 
a Cacouac, when the article Geneva put the Encyclopedic in jeopardy, when 
his relations with D Alembert and Voltaire were under almost as great 
stress as were his relations with Rousseau. The strain of such events no doubt 
made it more difficult to maintain his balanced judgment in regard to Rous 
seau, just as his worsening relations with Rousseau probably affected ad 
versely the other crises through which he was living. Reciprocally, one mag 
nified the other. 

Rousseau was meanwhile living on at the Hermitage, to all outward ap 
pearances calm, nevertheless seething within. His agitation was partly caused 
by an extremely sensitive and imaginative nature, which impelled him to^be 
suspicious of the motives of his friends and created an appalling conviction 
of ever-threatening menace and ever-darkling doom. Partly his excitement 
came from meditating upon what was to become his great love story, La 
Nouvelle Helo ise. Rousseau was in the grip of a tumultuous and irresistible 



passion. He was in love with love. And, as usually happens to men in that 
condition, it was not long before his affections lit on a person who seemed 
to him to be the very incarnation of his dreams. 

This lady, whom he had known slightly for several years, was Sophie, 
Countess d Houdetot, the sister-in-law of his benefactress, Mme d Epinay. In 
her person the Countess connects the French Enlightenment with the early 
days of the Republic of the United States, for Ambassador Thomas Jefferson 
frequented her social circle and found her charming. Now twenty-seven, 
she had married at the age of seventeen, had separated from her husband, and, 
when Rousseau fell in love with her, was living at Eaubonne, not far from 
the Hermitage. Mme d Houdetot was a young woman full of high spirits, 
far from overserious, capable of witty badinage, and endowed with a fair 
share of coquetry. She could, moreover, turn a pretty piece of verse, and en 
couraged the supposition that she was the authoress of a much esteemed 
Hymn to Breasts, written, it was suspected, for the purpose of stimulating 
curiosity regarding her own. 1 

The course of true love was troubled by some rather fundamental draw 
backs. In the first place, the lady was not very much in love with Rousseau, 
if at all, although she seems to have been flattered by his attentions. In 
addition, she was already the mistress of another man, a man to whom she 
was to remain faithful for fifty-one years. Her lover was the Marquis de 
Saint-Lambert, a soldier and poet who some years earlier, because of his 
capacity for begetting, had been the indirect cause of the death of Mme du 
Chatelet. His liaison with Mme d Houdetot had begun in 1752.2 Now, in 
this crucial spring and summer of 1757, he was on active duty with the French 
army in Westphalia, where he now and again saw Grimm, and from whom 
he seems to have learned that Mme d Houdetot was seeing more of Jean- 
Jacques than could be regarded as discreet. This was the end of the idyllic 
phase of Jean-Jacques s love affair. Saint-Lambert evidently rebuked Mme 
d Houdetot. She in turn told Jean-Jacques, who hotly accused Mme d Epinay 
of informing Saint-Lambert. This was an accusation that Mme d Epinay 
found hard to forgive, and it is difficult to say whether much friendship was 
left between her and Rousseau after the day of the five notes, occurring in 
late August of I757* 3 

Throughout this prolonged crisis the much bedeviled Rousseau tried to 
conceal two pieces of material information, as a result of which all the other 
protagonists in the imbroglio, particularly Diderot, felt as though they were 
groping in the dark. In the first place, Rousseau was very reluctant to admit 
that he was in love with Mme d Houdetot. It was transparent enough to any- 


one who lived in his society, yet he never admitted it to Mme d Epinay nor 
to Grimm nor to Saint-Lambert, and he clearly implies that he did not con- 
fess to Diderot that he was in love until the last interview that they ever 
had, which took place at the Hermitage on 5 December 1757. But even then 
he concealed from Diderot a second bit of material information. As he him 
self wrote in his Confessions regarding this conversation, 1 never admitted 
that Mme d Houdetot knew of it or at least that I had declared it to her. * 
Rousseau had of course declared his love. But his situation was perplexing 
and delicate, for Mme d Houdetot was not supposed to be fancy-free. Rous 
seau, moreover, was under moral obligation not to take advantage of a man s 
absence to alienate the affections of his mistress. In these circumstances, 
Rousseau s high reputation for virtue being what it was, he was subject to 
the subtle temptation of awakening her moral scruples with regard to her 
liaison with Saint-Lambert. Rousseau s passion for Mme d Houdetot is a re 
warding subject for study in the casebook of the psychology of love. Every 
man is a Saint Anthony, but the forms in which temptation appears are 
various. The almost infinite capacity for subconscious self-deception, for con 
fusing virtue and desire, is nowhere better shown than in the paradoxical, 
hypocritical, and pathetic figure of the austere citizen, the stern, republican 
man of virtue, overwhelmingly tempted to arousing conscientious scruples 
in another man s mistress hi the hope of seducing her himself. Of course 
Rousseau never put it this way to himself, yet he came close in his Con- 
fessions and in his letters to Saint-Lambert to admitting that this was what 
he was about. *I protest, he wrote in the Confessions, 1 swear that if, some 
times carried away by my senses, I attempted to make her unfaithful, never 
did I truly desire it. And in a letter to Saint-Lambert, he wrote, I deprecate 
your connection . . . but a love such as yours merits some consideration, and 
the good it produces renders it less culpable. 5 Indeed, Saint-Lambert s princi 
pal uneasiness regarding the attentions Rousseau was paying to Mme d Hou 
detot seems to have arisen from just this apprehension that the citizen would 
undermine her attachment for Saint-Lambert by playing upon her scruples: 
I reserve, however, your promise which you give me of never speaking to 
her against our connection. . . . 6 And Saint-Lambert might well think that 
there was ground for worry when he read Rousseau s reply, in which the 
citizen remarked that I told her that her attachment for you was henceforth 
a virtue ! 7 When some time later the exasperated Diderot was drawing up 
a list of Rousseau s malfeasances Citizen Rousseau committed seven ras 
calities simultaneously, which have alienated all his friends one of the 
rascalities was listed as follows: *M. Rousseau then fell in love with Madame 



d Houdetot; and to prosper his affair, what did he do? He sowed scruples 
in the mind o this lady regarding her passion for M. de Saint-Lambert, his 
friend. * Authorities are in pretty general agreement that here Diderot de 
scribed the situation as it truly was. 9 

When this nightmare of tangled personalities began, Diderot s relationship 
to it was extremely peripheral. At this time in his life he had not even met 
Mme d Houdetot, he had just barely made the acquaintance of Mme d Epinay 
and was reluctant to know her better, and he rarely saw Rousseau, who was 
at the Hermitage, or Grimm and Saint-Lambert, who were on active duty 
in the field. Although a whole book about this quarrel has been written on the 
assumption that Diderot was in a plot against Rousseau and pursued him 
step by step, the record seems to show more casualness than calculation. It is 
nearer the truth to think of a bumbling Diderot than a conspiratorial Diderot, 
of the nonchalant Diderot who antagonized his friends by not writing an 
expected letter or by absent-mindedly failing an appointment, of the naive 
Diderot who was maddening in proffering unsolicited advice and ingenuous 
in the admiration of his own virtue. 

In the history of the friendship of Diderot and Rousseau, the year 1757 
had begun with bickerings about Mme Levasseur and about the offensive 
remark made by Diderot in Le Fils natural Diderot, who had been promis 
ing for a long time to go to the Hermitage, finally arrived there in early 
April, and a very satisfactory reconciliation seems to have taken place. 10 
Then, in July, Rousseau stayed two nights at the Rue Taranne. The initia 
tive for this meeting was evidently Rousseau s, his object apparently being 
to make sure that Diderot would at last be brought to giving his opinion and 
suggestions concerning the manuscript of La Nouvelle Helo ise* In his Con 
fessions Rousseau says that he had sent Diderot the first two parts of the 
novel about six months previously, but that Diderot had not yet read them. 
Besides this, Rousseau claims to have had the generous motive of desiring to 
help Diderot, the latter being involved just at this time in the crisis regarding 
the plagiarism of Goldoni, and to signify to the world by this visit that the 
two men had not quarreled. 11 In the anti-Rousseau camp the tradition re 
garding this visit was that Rousseau kept Diderot slaving at the revision un 
til all hours, then discreditably refused to listen to something of Diderot s 
when the latter wanted Rousseau s advice in return. 12 

Years afterward, in recollections clustering around these events, Diderot 
and his friends asserted that he visited the Hermitage and Montmorency 
very frequently during all the time that Rousseau was resident there. Thus 
Mme de Vandeul wrote that all the time that he stayed at Montmorency, 


my father had the constancy to go there on foot once or twice a week to 
dine with him. 13 Marmontel quotes a similar declaration by Diderot: 
*. . . and I [he says Diderot declared] going on foot two or three times a week 
from Paris to his hermitage/ 14 Moreover, Morellet claimed in his Memoires 
to have participated in these expeditions himself. Often we went, Diderot 
and I, from Paris to his hermitage near Montmorency to pass whole days 
with him. There, under the great chestnut trees adjacent to his little house, I 
have heard long extracts from his Helo ise, which enraptured me as much 
as they did Diderot. . . . 15 

The testimonies of Mme de Vandeul, Marmontel, and Morellet were 
written down many years after the events they purport to describe. Mme de 
Vandeul s and MarmontePs remarks indicate that their sole authority was 
the assertions made by Diderot. Morellet, on the other hand, claims to have 
been an eyewitness. Yet his testimony is very hard to reconcile with the tone 
of the letters that Rousseau was writing, not years later in his Confessions, 
but at the very time of these alleged events. These show that all through 1757 
Rousseau was greatly distressed that Diderot came so seldom to the Hermitage. 
Indeed, Rousseau s letters allow us to trace only four times, and no more than 
four times for certain, when Diderot and Rousseau saw each other face to face 
in the year 1757. Perhaps the frequent visits Morellet spoke of occurred in 
1756, but the difficulty regarding this possibility is that Rousseau could not 
then have read to them his Nouvelle Heloise because he did not begin to write 
it before early 1757, when his relations with Diderot were already extremely 
strained. To speak bluntly, Morellet s story does not hold water. 

Regarding the four meetings between Rousseau and Diderot in 1757, we 
have already spoken of three. These were: the occasion in January when 
Rousseau went to Paris to be at the bedside of Gauffecourt; the one in April, 
when a reconciliation occurred at the Hermitage; and that in July, when 
Rousseau spent several nights at the Rue Tarannc. The fourth meeting 
the last in their lives was at the Hermitage in early December. Over and 
above these, there may have been and probably was a fifth occurring early in 
September at the Hermitage. If it did occur, it was because Rousseau was in 
urgent need of advice, his relations with Mme d Epinay, Mme d Houdetot, 
and Saint-Lambert having suddenly become extremely vexed and compli 
cated as a result of the agitation caused by the day of the five notes* (probably 
31 August). According to Diderot s Catalogue of the Seven Rascalities, 
Rousseau accused Mme d Epinay of either informing M. de Saint-Lambert 
or having him informed of his passion for Mme d Houdetot. Embarrassed 
by his conduct with Mme d Houdetot, he called me to the Hermitage in 


order to learn what to do. I counseled him to write M. de Saint-Lambert 
everything, and to keep away from Mme d Houdetot. This advice pleased 
him, and he promised me that he would follow it. 16 Although many 
authorities make no allowance for this September interview, the fact that 
Rousseau did write a long letter to Saint-Lambert on 4 September makes it 
seem very possible that the letter was written pursuant to Diderot s advice. 17 
Diderot further declared, in his enumeration of the seven rascalities, that 
Later I saw him again. He told me that he had done it and thanked me 
for the advice. . . . 18 Rousseau s letter of 4 September is the only one that 
fills these specifications. But it is much less candid than Diderot claims 
to have advised. 

If Jean-Jacques was driven to distraction by his love affair, it is well to re 
member that Diderot, too, had recently become involved in one of his own. 
And during September and October of 1757, when his wife and little 
Angelique were at Langres on a three-month visit, he had three or four 
bouts of fever, which debilitated him precisely at the time when Rousseau s 
relations with Grimm were being stretched to the breaking point. Grimm 
returned from campaigning and was with Mme d Epinay through those 
months. Being jealous of Rousseau s ascendancy over Mme d Epinay, Grimm 
treated Jean-Jacques very haughtily, with that calculated hardness that was 
an unpleasant part of his character. The incidents in this process of disattach- 
ment may be followed at length in Book IX of Rousseau s Confessions. 19 At 
the same time the decision was shaping up that Mme d Epinay, whose health 
had been poor for some time, should travel to Geneva to be under the care 
of Dr. Tronchin. She herself did not put much emphasis into her proposal 
that Rousseau, who knew Geneva well, should accompany her thither. But 
Diderot did, in a letter written about mid-October which threw Rousseau 
into a tantrum. *I learn that Mme d Epinay is going to Geneva, but I do not 
hear it said that you will accompany her. . . . Overburdened as you are with 
the weight of the obligations you owe her, here is an occasion for paying her 
back in part and for relieving yourself/ Then, after discounting in advance 
Rousseau s protestations of ill health, Diderot continued: Moreover, aren t 
you afraid that your conduct will be misinterpreted? You will be suspected 
of ingratitude or of some other secret motive. I know very well, whatever 
you do, that you will have in your behalf the testimony of your conscience; 
but does this testimony suffice by itself? And is it permissible to neglect the 
conscience of other men up to a certain point? ... I salute you, love you, 
and embrace you. 20 


The enraged Rousseau at once accused Diderot of a plot. 21 Once Rous 
seau s suspicions were aroused, his lively imagination always carried him very 
far. Sometimes he realized this himself. For instance, he once took it into his 
head that his publisher, being delayed in sending him the proofs for Emilc, 
was betraying him by giving the manuscript to the Jesuits. When Malesherbes 
wrote to soothe him, Rousseau remorsefully replied, Oh! Monsieur, I have 
done an abominable thing. . . . Nothing has changed since the day before 
yesterday, yet everything now takes on in my sight a different complexion, 
and where I thought I saw the clearest proofs I now see only some very 
ambiguous indications. Oh! how cruel it is for a sick and melancholy man, 
living alone, to have an unregulated imagination and to be informed of noth 
ing concerning himself. 22 

In scarcely any circumstances could Rousseau endure being told what 
to do. Moreover, if two of his friends were in agreement as to any course he 
should pursue, he promptly concluded that a conspiracy was afoot against 
him. And to allege that he had obligations to some person drove him quite 
frantic. Much can be said in justification of this sturdy love of independence, 
although it can scarcely be denied that Rousseau put himself into an ambigu 
ous light, to say the least, by accepting the occupancy of the Hermitage. 
Rousseau s awkward position is by no means an unusual one. Multitudinous 
are the men of letters and the artists of every generation whom ambitious 
hostesses and lionizing friends have sought to put under obligations by the 
very extent of their generosity. Perhaps the only defense against this con 
stricting menace of being loved into sterility is to adopt the practice of ac 
cepting favors without incurring a sense of obligation for them. Rousseau 
made the mistake, however, as did James I and Charles I, at odds with their 
parliaments, of argiiing about it. His long letter to Grimm, dated 19 Octo 
ber, in which he referred to his two years of slavery at the Hermitage, 
gave Diderot ample reason for asserting that Rousseau Vrote against Mme 
d Epinay a letter that is a prodigy of ingratitude. 23 

So Rousseau did not offer to accompany Mme d Epinay to Geneva and 
Diderot wrote this down as one of the seven rascalities. Among Rousseau s 
secret and unacknowledged reasons for not desiring to be seen with Mme 
d Epinay at Geneva was his suspicion that her motive for going was that 
she was with child by Grimm and that she intended to have the child in 
secret there. Actually this was not the case Mme d Epinay had some sort 
of bona fide abdominal ailment but inasmuch as she had previously had 
an illegitimate child by M. de Francueil, a circumstance of which Rousseau 


might quite well have been aware, his suspicions, though he could scarcely 
acknowledge them in writing and though they happened to be unfounded, 
were nevertheless not preposterous. 24 

Mme d Epinay left for Geneva on 30 October, and a few days later Grimm 
wrote Rousseau, castigating him for his horrible apology and his mon 
strous system. ... I shall never in my life see you again, and I shall deem 
myself fortunate if I can banish from my mind the recollection of your be 
havior >25 

In view of the situation, Rousseau began to feel that he should leave the 
Hermitage. Mme d Houdetot counseled against it, fearing that such a move, 
occurring just at the onset of the worst season of the year when most peo 
ple avoided the unpleasantness of moving, would cause a great deal of 
gossip and perhaps make Rousseau s passion for her common knowledge. 
Thinking that Diderot would advise the same thing, she wrote to him, 
although they were not yet personally acquainted, offering to take him to 
the Hermitage and to be present at the interview. Diderot replied that if she 
was present he would find it impossible to speak frankly: 1 am of an ex 
treme timidity, he wrote. And in a second letter he promised to go to the 
Hermitage on his own initiative as soon as he could. 26 Whether because of 
timidity or from fear of further complications, it is quite clear that he had 
no desire to become acquainted with Mme d Houdetot, and this feeling 
lasted at least into January, for Mme d Houdetot wrote Rousseau that she 
happened to meet Diderot at Baron d Holbach s 1 was wearing panniers 
and had my diamonds on and he fled from me. 27 Diderot wrote to 
Rousseau about mid-November, and did advise him not to leave. In the 
course of the letter he denied the existence of the plot that Rousseau was so 
sure his friends had organized. 28 

Early in December Diderot at last found the time to go to the Hermitage. 
Although Diderot says in his Catalogue of the Seven Rascalities that he 
went to the Hermitage to demand of Rousseau why he had not confessed 
to Saint-Lambert as he had told Diderot he had done, the tone and sequence 
of Rousseau s Confessions and of his correspondence at this period do not 
confirm this at all. In fact, the Saint-Lambert affair did not come to its 
climax until several months later. On the contrary, the conversation during 
the December meeting seems to have concerned itself with the Mme 
d Epinay-Grimm crisis, with Rousseau s unsuccessfully trying to get old 
Mme Levasseur to confirm that Mme d Epinay had attempted to suborn her 
and Therese. No doubt there was a good deal of discussion as to whether 
Rousseau should leave the Hermitage, now that midwinter was coming on, 


and Rousseau further claims that this was the occasion when he learned 
what was for him the very upsetting intelligence that D Alembert, in his 
article on Geneva/ was undertaking to tell the citizens of Jean-Jacques s 
native city what they should do. 28 

One can well imagine that such an interview, between persons so articu 
late, demonstrative, and emotional, was very much like a scene from one 
of Diderot s dramas. Tempestuous as it must have been, it nevertheless was 
far from ending in a break. It was in fact the last time that the two men 
met, but this was not their expectation at the time. The proof lies in the fact 
that a few days later Mme d Houdetot wrote to Rousseau proposing that 
instead of his moving to Montmorency from the Hermitage, he should go 
to live with Diderot for the winter. Rousseau s reply, while deeming the 
project unfeasible, shows that he did not suppose that he would be unwel 
come. Do you know my situation well enough? he asked. e Do you know 
his, the temper of his wife, to be sure that that is practicable ... ? 30 

Rousseau moved from the Hermitage into the town of Montmorency on 
15 December 1757. In February he wrote to Diderot what appears to have 
been a friendly letter urging him to give up the Encyclopedic if D Alembert 
did, for this was just at the height of the turmoil caused by the article on 
Geneva. He did not even deign to answer me, wrote Rousseau to Mme 
d Houdetot, and thus he leaves in adversity the friend who so eagerly 
shared his [at Vincennes]. That is all that is necessary on his part. This 
abandonment tells me more than all the rest. I cannot cease to love him, 
but I will never see him again in my life. 31 Yet Diderot was really not un 
mindful of Rousseau s situation, for Deleyre, a friend they had in common, 
wrote on 28 February, He [Diderot] is as uneasy as I regarding the resources 
that remain to you for subsisting. He fears lest you be in need at the present 
moment. 32 This month and even early in March, Deleyre as well as Mme 
d Houdetot herself were writing to Rousseau of the likelihood of Diderot s 
paying a visit to Montmorency. 33 Then, on 2 March, Rousseau wrote a let 
ter, apparently never answered it was not just Voltaire who could not 
extract replies from Diderot in which he stated that he had heard that 
Diderot was blackening his character and imputing horrible things to him. 
I must, my dear Diderot, write you once more in my life. . . * I am a bad 
man, am I? he asked, and then he wrote, clearly alluding to Grimm, I 
should like you to reflect a little about yourself. You trust your natural 
goodness. . . . What a fate for the best of men to be misled by his own 
candor and to become, in the hands of bad persons, the innocent instrument 
of their perfidy. I know that self-esteem is revolted by this idea, but it merits 


the examination of reason. . . . You could have been seduced and misled. 
. . . Diderot, think about this. I shall not speak to you about it again. 34 

And now for the catastrophe. Saint-Lambert, having been invalided at 
Aix-ia-Chapelle for several months, returned to Paris in March I758. 35 He 
seems to have learned quite quickly that Rousseau s attentions to Mme 
d Houdetot had been altogether more determined and passionate than he 
had ever supposed or had ever been led to believe. This being true, Rous 
seau s letter of 4 September took on an altogether different aspect. Although 
at the time he had answered it in friendly fashion, it now seemed to him 
to be a hypocritical document. 36 As Diderot said of Rousseau in his Cata 
logue of the Seven Rascalities, he wrote an atrocious letter, of which M. de 
Saint-Lambert remarked that one could reply to it only with a stick. 37 
Following upon this unpleasant discovery, Saint-Lambert used his influence 
with Mme d Houdetot to cause her to break off all relations with Rousseau, 
which she did in a letter of 6 May, complaining that these rumors have 
come to my lover for some little time. . . . [because of] your indiscretion 
and that of your friends. 38 For Rousseau this was a thunderclap. Feeling 
certain that it was Diderot who had informed Saint-Lambert and that he 
had perfidiously divulged confidential information, Rousseau not long after 
gave public notice that the friendship between him and Diderot was ended. 

Was there, really, any perfidy involved? Ah! don t we all wish that we 
knew. Nor perhaps shall we ever, for the motivations are probably as deeply 
concealed and the points of view as various as those portrayed in The Ring 
and the Boo\. Diderot stoutly asserted that there was no perfidy. After 
Saint-Lambert s return from the army, Diderot wrote in his Catalogue of 
the Seven Rascalities: He came to see me. Persuaded that Rousseau had 
written to him along the lines we had agreed upon, I spoke to him [Saint- 
Lambert] regarding this adventure as of an episode that he must know about 
better than L Not at all, for it turned out that he knew things only by 
halves and that, by Rousseau s falseness, I fell into an indiscretion. 39 

Had Diderot desired to be perfidious, this was the precise point where 
double-dealing would be most effective and least detectable, Diderot liked 
to suggest, in defense of his innocence, that proof of Rousseau s badness was 
that he had lost all his friends. Our friends that we had in common have 
judged between him and me. I have kept them all, and none of them re 
mains his, Diderot wrote to a Swiss pastor early in I759- 40 The statement 
is not quite true, for Deleyre, the minor Encyclopedist who had written the 
article Tin and who for a time in 1756 and 1757 was editor of the Journal 
Etranger, remained friendly to both. But even so, one must acknowledge the 


possibility that the defection of Rousseau s friends is not of itself proof of 
his being in the wrong. It might have resulted from unscrupulous manipu 
lation of the evidence. 

An attempt to determine the merits and motives in this tortuous story 
of six lives is of intrinsic interest as a study in human nature. Furthermore, 
it throws light on the personalities and characters of persons who are im 
portant in the intellectual history of the Western world. It reveals Diderot 
as much as Rousseau, each claiming to be justified, each standing on the 
threshold of crisis. The enemies of both used the quarrel as evidence to the 
discredit of each. And the break between Diderot and Rousseau came just 
at the time of, indeed was a part of, the more important crisis in the fate 
of the Encyclopedic. Here Diderot walked in peril, walked almost alone. 
It was the greatest test he had been called upon to undergo the greatest 
in his life. To survive it required resources of stoicism, self-confidence, en 
durance, and conviction that make him one of the heroes, or if it be 
thought that his sense of self -righteousness is too great to allow him heroic 
stature one of the near-heroes, as he was certainly one of the seminal 
figures, in the history of thought. The mind therefore returns again and 
again to the problem of the sincerity and honesty of the man who was 
presently to undergo such a searching test of his stamina and nerve. Was 
Diderot as virtuous as he thought he was? 

Probably not. It is vouchsafed to few men to be that virtuous. But in his 
behalf it may safely be said that to establish that he was perfidious in his 
relations with Rousseau, one would need to prove a degree of forethought, of 
calculation, and of ruthlessness that, although they may have existed in this 
instance, are most contrary to the usual tenor of his ways. Through all the 
months of this crisis, Diderot had no consistent policy regarding Rousseau. 
Of course it is true that during this crucial time Diderot was in daily asso 
ciation with Grimm, the man who had become Rousseau s bitterest enemy, 
and it is altogether probable that by the attrition of constant innuendoes 
Grimm was able to wear away a great deal of Diderot s lingering sympathy 
for Rousseau. But this does not seem to have resulted in any calculated 
policy on Diderot s part. His attitude remained passive, not active. What 
he did seems to have been the result of sudden impulse. His was the attitude 
and conduct of a man who, as Voltaire said of him at just this moment, 
found it harder to write a letter than a book. 41 Moreover, the tension with 
Rousseau was by no means the only preoccupation of these anxious times. 
It is hard to believe, with so much going on, with trying to finish Lc Pere 
de jamille and edit the eighth volume of the Encyclopedic and contend with 


a reinvigorated censorship and parry the attacks of pamphleteers and deal 
with Voltaire and persuade D Alembert to stay with the Encyclopedic, that 
he could think of the Rousseau problem by much more than fits or starts, 
or spend his time in contriving a plot against his former friend. 

Besides, Diderot probably did not lie when he stated in his Catalogue of 
the Seven Rascalities, a list that was drawn up not later than 1760, and as 
serted at about the same time to Marmontel that Rousseau had asked for 
advice about Saint-Lambert and had promised to follow it. 42 Even this can 
not be established beyond a doubt, and of course it is always possible that 
Diderot, without in any way being involved in calculated perfidy against 
Rousseau, did thoughtlessly blurt out to Saint-Lambert confidential infor 
mation that ought to have been withheld, a lapse that he thereupon under 
took to justify instead of frankly acknowledging. Nevertheless the fact that 
Rousseau did write to Saint-Lambert the long letter on 4 September re 
garding Mme d Houdetot suggests that Rousseau had accepted Diderot s 
advice and that Diderot could assume that Saint-Lambert was fully in 
formed. If this be so, then Rousseau really misled Diderot about what he 
had said in that letter, thus being the real cause of Diderot s inadvertently 
committing an indiscretion. And then, to Diderot s indignation, Rousseau, 
the cause of this false step, turned on Diderot and by a public break exacted 
double indemnity for the offense. As Professor Torrey remarks, Diderot felt 
taken in.* 3 One can sense Diderot s exasperation and feeling of outrage in 
the very language and style of the Catalogue of the Seven Rascalities, It 
breathes the sense of injury of a man who honestly feels much put upon, 
rather than the factitious indignation of a conspirator simulating wrath. 44 

Following the interview with Saint-Lambert in which, according to his 
own account, Diderot was inadvertently indiscreet, he did nothing. There 
was no more talk of his going to Montmorency, there were no letters ex 
changed, there were no upbraidings. It was Rousseau, not Diderot, who took 
the initiative in notifying the public that the friendship had come to an 
end. On 6 May, Mme d Houdetot broke off relations with Rousseau, and 
this was followed by Saint-Lambert s going to Montmorency a couple of 
times, as a result of which Rousseau decided that it was Diderot who had 
treacherously betrayed him. 45 Consequently, in the preface to his forthcom 
ing Letter to D Alembert, he gave public notice of the break: Taste, dis 
crimination, correctness, will not be found in this work. Living alone, I 
have been unable to show it to anyone. I used to have an Aristarchus, severe 
and judicious. I have him no longer, I wish to have him no longer; but I 
shall regret him ceaselessly, and he is missing a great deal more from my 


heart than he is from my writings. To this was appended a footnote, a quo 
tation in Latin from the Book of Ecclesiasticus : Hast thou drawn sword 
against thy friend? Be comforted; all may be as it was. Hast thou assailed 
him with angry words? Thou mayst yet be reconciled. But the taunt, the 
contemptuous reproach, the secret betrayed, the covert attack, all these mean 
a friend lost. 46 

When Deleyre, still friendly to both men, saw the celebrated footnote, he 
wrote to Rousseau, What a passage from Scripture you proceed to quote! 
You don t want friends any more, then, since you renounce the best one 
that by your own admission you ever had. 47 Marmontel s Memoirs reveal 
the way in which this footnote was regarded in the circle of Diderot s friends. 
Finding myself alone with Diderot for some minutes on one occasion, I 
expressed my indignation, apropos of the letter to D Alembert on plays, 
concerning the note that Rousseau had placed in the preface of this letter. 
It was like a stiletto thrust. . . . Everyone knew that it was Diderot to 
whom this infamous note was addressed, and many people thought that he 
must have deserved it since he did not refute it. 

Diderot replied to Marmontel that he could not defend himself against 
Rousseau s imputations without involving others. It is cruel to be calumni 
ated, he said, and that basely and in the perfidious accents of friendship 
betrayed, and [it is cruel] not to be able to defend oneself. But such is my 
position. You shall see that my reputation is not the only one involved. Now, 
as long as one can defend one s honor only at the expense of some one 
else s, one must remain silent, and I do. 48 

Saint-Lambert, like Deleyre and Marmontel, was strongly and unfavor 
ably impressed by the famous footnote. Rousseau had presented him with a 
copy of the Lettrc Z D Alembert, only to receive this reply: Truly, Mon 
sieur, I cannot accept the present you have just made me. At the place in 
your preface where, regarding Diderot, you quote a passage from Ecclesi- 
astes [Ecclesiasticus], the book fell from my hands. After the conversations 
of this summer, you appeared convinced that Diderot was innocent of the 
alleged indiscretions that you imputed to him. He may behave badly with 
you. That I would not know. But I do know that he does not give you 
the right to give him a public insult. You are not ignorant of the persecu 
tions he is undergoing, and yet you are going to add the voice of an old 
friend to the cries of envy. I am unable to conceal from you, Monsieur, 
how much this atrocity revolts me. I am not intimate with Diderot; but I 
honor him, and I feel keenly the sorrow you cause to a man whom, at least 
in my presence, you never reproached with anything but a little weakness " 



Rousseau s preface was an attack masquerading as a defense, and con 
troversy has raged over the question of who did whom wrong, much as 
scholars winnow the evidence regarding a question of war guilt. Diderot 
was not only deeply upset by the footnote in the preface, but also by the 
tenor of the whole book. Rousseau, in taking issue with D Alembert as to 
the desirability of having a theater at Geneva, used arguments or illustra 
tions that Diderot regarded as slurs or attacks upon himself. Accordingly he 
burst forth in passionate resentment of what he conceived to be Rousseau s 
malfeasances: His note is a tissue of infamy. I have lived fifteen years with 
that man. Of all the marks o friendship that a man can receive, there is 
none he has not had from me, and he never gave me any in return. . . . 
this man is false, vain as Satan, ungrateful, cruel, hypocritical, and bad 
.... Truly this man is a monster. 50 

For almost all the philosophes, and pre-eminently for Diderot, it was a 
very sore point to allege, as Rousseau had done in the Lettre & D Alembert, 
that it is impossible to be virtuous without first being religious, impossible 
to have probity without religion/ To the contrary, Diderot insisted that 
the two are entirely separable. He had found Lord Shaftesbury s ideas very 
attractive because die noble earl had made precisely this distinction, it being 
an important implication in the Inquiry concerning Virtue and Merit which 
Diderot had translated in 1745. A man could be virtuous, according to this 
view, without being inspired by the fear of hell Indeed, he could be more 
virtuous, because he was animated by a love of virtue for its own sake. 
It was this line of thought that involved Diderot in a great deal of moraliz 
ing, an activity that he confessed he greatly enjoyed. Everyone has his 
idiosyncrasy, he wrote about 1773-4, and mine is to moralize. 51 Diderot 
wanted to prove that philosophes were better men than Christians were. 
He wanted to believe that he himself was a more virtuous man than his 
brother, for example, who was a priest. Consequently he scarcely ever tired 
of talking about virtue. 

This sort of compulsion is well illustrated at this very time by Diderot s 
long response to a pastor in Geneva, probably Rousseau s friend, Vernes. 
Apparently Diderot was replying not only to words of praise but also to 
some tactfully phrased inquiries regarding the merits of the break with 
Rousseau. Probably Vernes was trying to discover whether there was any 
possibility of reconciliation. At all events, Diderot launched into a discus 
sion of morality. It is not Diderot at his best. It is wordy and a little illog 
ical. Moreover, the ideas in it give rise to the uneasy feeling that they were 
designed more to match the receiver s cloth than the sender s deepest be- 


liefs. But there the letter is, in the Bibliotheque Publique et Universitaire 
of Geneva, with Diderot s signature upon it, testifying to what he said were 
the views he held regarding virtue. Diderot referred to himself as a man 
esteeming virtue to such a point that I would gladly give what I possess 
in exchange for having been up to the present moment as innocent as I was 
when I was born, or in exchange for coming to the end forgetful of the 
errors I have committed but conscious of not having increased the number 
of them! The more one scrutinizes the latter half of this statement the 
more oracular and turgid it seems to become. Diderot continued by remark 
ing that Virtue is, then, the greatest wealth of him who enjoys life and 
the most substantial consolation of him who is about to die. There is nothing 
in the world, accordingly, to which virtue is not preferable; and if it does 
not appear to us to be so, that is because we are corrupted and not enough 
of it is left to us to make us aware of all its value. Then, passing to Rous 
seau, Diderot wrote, It is an atrocious action to accuse publicly an old 
friend, even when he is guilty. But what name can be given to the action 
if it happens that the friend be innocent? And what name, furthermore, 
should be given if the accuser avows to himself at the bottom of his heart 
the innocence of him whom he dares to accuse? And then Diderot made it 
clear that he was seeking no reconciliation: Tor twenty years he has taught 
me how to pardon private slights, but this one is public, and I do not know 
any remedy for it. 52 

Diderot might have been more forgiving had not the Lettre & TyAlembert 
been published at a time peculiarly unpropitious for him and for the Ency 
clopedic. Rousseau s Lettre, having received from Malesherbes a tacit appro 
bation, was on sale in Paris by 28 September I758. 53 It was not simply that 
this blast against the social utility of plays appeared less than a month before 
Le Pre de jamille, which, with its accompanying treatise on dramatic aes 
thetics, was intended to herald a new day in the theater. Scarcely anything 
could be better calculated to blunt the impact of the play or make Diderot s 
remarks about the drama, intended to seem self-evident, highly controverti- 
ble. This seemed grievous enough to Diderot, as his remarks in his Catalogue 
of the Seven Rascalities show. But more than that, the public character of the 
quarrel was very injurious to the pkilosophes, whether they deserved it or 
not. Up until this moment the public had thought of Rousseau as one of the 
Encyclopedists. He had been their leader in the controversy over Italian 
music, he had written the articles on music in the Encyclopedic, he had been 
the author of the important article on Political Economy, and Diderot had 
apostrophized him by name in the article Encyclopedia. 54 Oh! Rousseau, 


my dear and worthy friend/ Diderot had written for everyone to read in 
1755; and now the dear and worthy friend was advertising to the wide 
world that Diderot was unworthy of further friendship because of the 
covert attack and because of the secret betrayed. 

What Rousseau probably did not realize, but what Diderot and his friends, 
living in the hurly-burly of Paris could not forget, is that this quarrel by 
becoming public took on political significance. Rousseau s action, or, at least, 
Diderot s interpretation of it, can be thoroughly understood only in terms of 
its political context. Rousseau s Letter to D Alembert appeared in the course 
of, and greatly complicated, a prolonged crisis during which Diderot s for 
tunes seemed to proceed with inexorable step from portent to paroxysm to 
catastrophe. The writings about the Cacouacs were the portent, the conse 
quences of the publication in July 1758 of Helvetius unlucky book DC 
I Esprit was the paroxysm, the suppression of the Encyclopedic in March 
1759 was the catastrophe. In the whole eighteenth century this was the time 
of die crucial struggle to gain for one side or the other the support of public 
opinion. Eventually the Encyclopedic rose from its ashes. Eventually it be 
came manifest that the Encyclopedists had won public opinion to their side 
just when the course of events would seem to indicate the contrary. But the 
years of 1757, 1758, and 1759 were grim and anxious for Diderot, years in 
which public anxieties were compounded with private distress. And it was 
hard for him to forget that precisely at the time when his Encyclopedic was 
most beset by his enemies, precisely at a time when he most needed to prove 
that a philosophc was an upright man and pure in heart, Rousseau gratu 
itously informed the public that his old friend was a scoundrel. 

Inevitably, therefore, Rousseau s public denunciation, whether he realized 
it or not, assumed political significance. In consequence, the quarrel became 
a matter of consuming interest both to the friends and foes of the new 
philosophy. Everyone talked about it. To do so was more than a frivolity 
fit to fill up an idle moment. The implications of the quarrel were really of 
substantial interest to all. That an incident in the private lives of two middle- 
class writers could absorb the interest of the aristocratic society of the ancien 
regime to such a degree is a symbol of the revolution occurring in the French 
outlook. The Marquis de Castries, a nobleman destined to be a marshal of 
France, impatiently remarked one day when the quarrel of Diderot and 
Rousseau had become public knowledge, It s incredible. People don t talk 
of anything but of those fellows. Persons without an establishment, who 
don t have a house, who are lodged in a garret. One just can t get used to 
all that. 55 


Signs and Portents 
of Approaching Eclipse 

T^V ALEMBERT S decision in January 1758 to forsake 
.Lx the Encyclopedic, which he announced as being 
resolute and which on the contrary was succeeded by over a year of wavering 
and irresolution, ushered in a period of protracted crisis and confusion. 
Deleyre wrote to Rousseau on 25 January, during a spell of very cold weather, 
that There is the Encyclopedic spiked. It is no longer going, any more 
than the water mills have been running these past few days/ * The Journal 
Encyclopedique for i February mentioned that Vexations of all kinds have 
finally obliged M. d Alembert to give up the work absolutely and irrevo 
cably/ 2 Indeed, the publishers themselves announced to the public in an 
eight-page pamphlet that the work had been brought to a standstill. This 
communication, printed in Le Breton s shop and carrying the self-explanatory 
tide of Memoir of the Publishers Associated in the Encyclopedic regarding 
the Reasons for the Present Suspension of this Work/ must have been 
issued early in the year, for it was quoted lengthily in the Mercure dc France 
in April. A goodly portion of this pamphlet was devoted to wheedling 
D Alembert to return and, to judge from Diderot s informing Voltaire in 
June that D Alembert had consented to continue with the mathematical part 
of the work, it apparently wheedled with a measure of success. 3 As late as 
26 February, D Alembert had written to Voltaire, I persist in the resolution 
not to work any more on the Encyclopedic ; yet presently he is to be found 
doing the opposite of what he had previously announced and adopting a 
policy diametrically the contrary of what Voltaire had been counseling. 4 The 
fact is that D Alembert vacillated a good deal, much to the confusion of 
biographers, many of whom, putting his desertion in 1759 instead of 1758, 
seem to be unaware of how protracted and muddled the editorial crisis was, 



with D Alembcrt loudly announcing that he was quitting, then half-return 
ing, then quitting again, and even so late as February and April of 1759 
still considering staying on. 

The publishers appeal to D Alembert galled Diderot very much. We have 
the proof of this in a letter that he wrote about a year later to Sophie Volland. 
By this time D Alembert, who now had given up even the mathematical 
part of the Encyclopedic, saw Diderot for the first time in several months 
and rather lamely proposed being put onto the pay roll again. The fact was 
that he was hard up. He lived off pensions, though very modest ones, from 
the Prussian and French governments, and these were not being paid because 
of the fiscal stringencies induced by the Seven Years War. The occasion gave 
Diderot an opportunity to read D Alembert quite a lecture. When D Alem- 
bert declared that if he came back, he would write no more prefaces, Diderot 
replied, You might wish to write some in the course of time, and you 
wouldn t be free to. 

And why not? 

Because your previous ones have brought down upon us all the animosities 
with which we are now laden. Who is there who was not insulted in them? 

Alluding to the publishers public declaration in the pamphlet of the year 
before, Diderot said, Nevertheless you quit an enterprise into which they 
have put all their fortunes. An affair of two millions is a bagatelle not 
worthy of the attention of a philosopher like you. You entice away their 
contributors, you throw them into a complication of difficulties from which 
they will not soon extricate themselves. 5 All that you see is the slight satisfac 
tion of getting yourself talked about for a moment. They are under the 
necessity of addressing the public. You should see how they have regard for 
you and sacrifice me! 6 

In addition to causing him to tighten up the censorship of the Encyclopedic, 
D Alembert s article on Geneva prompted Malesherbes to re-examine the 
whole problem of the relation of the Encyclopedic to the government. The 
autograph draft of his memorandum, dated about April 1758 and now in 
the Bibliotheque Nationale, reveals a startling suggestion. In this letter sent 
to Bernis, who was then a member of the Royal Council and soon to become 
France s minister for foreign affairs, Malesherbes recommended a policy of 
complete autonomy and self-responsibility for the Encyclopedic. His letter is 
equally revelatory in the information it gives regarding Diderot s status in the 
eyes of the authorities: *As for M. Diderot, he has made some mistakes and 
he has been severely punished for them, but are these transgressions irrep 
arable? The disgraces he has already met with and the disfavor that he is 


still experiencing, since entry into the academies is forbidden to him for the 
present moment, are they not sufficient? 7 

Bernis reply was affable but noncommittal, and it is not known whether 
Malesherbes carried his project any further, or whether Diderot realized 
that the academies were closed to him. 8 When this decision, so adverse to 
Diderot, was made is not known, but it is clear that not only the French 
Academy but also the Academy of Sciences were closed to him, and it may 
perhaps be true that the provincial academies, which at that time were flour 
ishing everywhere in France, were aware of the official disapprobation of 
Diderot. This might explain why Diderot was never a member of an academy 
in France, no matter how provincial and obscure. 

D Alembert s decision in early 1758 to retire as an editor of the Encyclo- 
pedie evidently brought about a new contract between Diderot and the pub 
lishers, to judge by one of Diderot s rare letters to Voltaire. Even the latter, 
who had called Diderot cowardly for wanting to continue the venture, had 
changed his mind by June 1758, and had inquired whether Diderot would 
like him to contribute any more articles. 

Do I want your articles, Monsieur and dear master? [wrote Diderot on 
June 14]. Can there be any doubt about that? Shouldn t one make the trip 
to Geneva and beg them from you on one s knees, if they could be obtained 
at no other price? Choose, write, send, send often. I was not able to accept 
your offers sooner. My arrangement with the publishers is scarcely settled. 
We have made a fine contract together, like that of the devil and the peasant 
in La Fontaine. The leaves are for me, the grain is for them. But at least 
these leaves will be assured me. 9 

During the early summer of 1758 the preparations for publishing the 
eighth volume of the Encyclopedic were resumed. But the work was badly 
crippled by D Alembert s retirement, to judge from the statement of the 
publishers years later that his quitting was the reason for not publishing a 
volume in I758. 10 This time Grimm helped with the reading of proof, 
Diderot busied himself with his ordinary editorial tasks and with the prep 
arations for the publication of his play, Le Pere de jamillc, while the storm 
brought on by Rousseau s reference to the Book of Ecclesiasticus had not yet 
broken. 11 But whatever serenity Diderot may have been enjoying in the 
summer of 1758 was shattered in a twinkling by the publication in late July 
of the book by Helvetius, De I Esprit ( Concerning the Mind ). This treatise, 
which in spite of its name dealt more with the springs of ethical action than 
it did with psychology, had at first seemed so harmless that an official censor 
had approved it and it was published with tacit permission. All the evidence 


points to the fact that Helvetius himself did not dream that his book would 
be controversial, which seems to prove that he did not have a very lively 
sense of the grand strategy of politics, for De fEsprit put into grave jeopardy 
the cause it intended to serve. The orthodox regarded the book as the most 
shocking and outrageous that the century had yet seen in print, and they 
contended, moreover, that it was completely representative of the point of 
view of the philosophcs. Especially was this asserted of Diderot and the 
Encyclopedic. The two works were sedulously intertwined by the critics of 
both, although Helvetius never contributed any articles to the Encyclopedic, 
Nevertheless the latter was made to share by association in the general repro 
bation. In consequence, Diderot found himself living in an atmosphere of 
mounting tension and suspense. And before long, crisis was succeeded by 

DC I Esprit seems rather commonplace to a twentieth-century reader and 
reminiscent of that deathless line in the American theater, What s all the 
shootin fer? For Helvetius was simply attempting to found a science of 
morality on a basis of behaviorism without the use of transcendental sanc 
tions. As he remarked in his preface, 1 have felt that morality should be 
treated like all the other sciences, and that one should make an ethics as one 
makes an experimental physics. His doctrine now seems very much over 
simplified, but certainly familiar, indeed almost platitudinous. In fact, he 
was a predecessor of Jeremy Bentham and the utilitarian ethics based upon 
the pleasure-pain calculus. 12 A twentieth-century student of ethics is likely 
to take the basic assumptions of Helvetius regarding the moral nature of 
man as true as far as they go, but stated in a simplistic and rather perverse 

At the time of its publication, however, the orthodox, the conservative, and 
the conventional were profoundly shocked by the doctrines of Helvetius 
because he made his system of morality quite independent of the will of God 
or the behests of religion. There were no other-worldly sanctions. Egotism, 
so to speak, was to be its own reward. For Helvetius dressed up his ethics in 
the paradox of an exaggerated egotism, claiming that man was virtuous, 
when and if he was, only because in that fashion he best satisfied the de 
mands of his own ego. The famous Mme du Deffand remarked of the book 
that it upset everyone so much because Helvetius had revealed what was 
everyone s secret. 

Nor did Helvetius confine himself to views regarding psychology and 
ethics. He unburdened himself of a variety of obiter dicta, particularly in 
his footnotes, which were as inflammatory as they were extraneous. He dis- 


approved of the burdensome forced labor on the highways, he declared that 
savages were happier than the French peasantry, he attacked the Catholic 
priesthood as not being attached to the general interest/ he wondered 
whether the Catholic practice of getting rid of daughters by forcing them to 
take the veil was not more barbarous than the infant exposure of the Chinese, 
he inveighed against luxury, he insisted (thinking of the belief in miracles) 
that evidence must be statistical and based on the calculation of probabili 
ties/ he praised Julian the Apostate, he very clearly implied that there was 
no real metaphysical difference between men and animals, and he delivered 
himself of such humanitarian generalizations as not a hogshead of sugar 
arrives in Europe undyed by human blood. 13 

Helvetius 1 book is by no means an unalloyed delight to read, even for 
those who enjoy collecting antiques. It tiresomely reflects his egotism and 
humorlessness. The view of human motivation is very narrow. Conduct is 
motivated almost exclusively by self-esteem, the thirst for fame, and the 
desire for women, thus mirroring its author more than man. 14 De I Esprit 
is diffuse. It is repetitious. It shifts ground confusingly by taking advantage 
of the extraordinary semantic complexities of the word esprit! Some of the 
time the book is talking about mind, some of the time about wit, and some 
of the time in special senses of the word peculiar to Helvetius, as when he 
makes esprit equivalent to taste* and to expertness. Although metaphors 
and similes are profuse, the effect is surprisingly uninteresting because his 
imagery is commonplace and unimaginative and his presentation pedestrian 
and dull. Diderot remarked of the book that A paradoxical author ought 
never to state his conclusion but always his proofs. He should enter into the 
mind of his reader slyly, and not by force. ... If all that the author wrote 
had been heaped up pell-mell, so that there had been only in the mind of the 
author an unacknowledged principle of arrangement, his book would have 
been infinitely more agreeable and, without appearing so, infinitely more 
dangerous/ 15 

De I Esprit was published on 27 July 1758. On 10 August the Council of 
State revoked the license for its publication, and this was followed in turn 
by fulminations from the Archbishop of Paris (22 November) and Pope 
Clement XIII (31 January 1759) , ie The unfortunate censor of the book, one 
of the chief clerks in the Ministry of Foreign Affairs, a man named Tercicr, 
lost his job for having passed the manuscript, and Helvetius himself was 
deprived of the honorific position he had held of maitre d hotel of the Queen 
of France. 17 He also had to make a series of solemn retractions. 18 Beyond 
this, upsetting enough for many men but apparently not very distressing to 


Helvetius, nothing much happened to him. As the clearheaded Turgot 
remarked, what Helvetius had done was the most suitable for drawing down 
upon him the notoriety of being persecuted, which does not do much harm 
to a rich man, and to make the real weight of it fall upon a large number 

of honest men of letters who get the lash that Helvetius deserved 19 

Precisely the same point was made by Grimm, who was particularly alarmed 
because of Diderot s association with Helvetius in the public mind. Philoso 
phy will feel the effects for a long time of the upheaval of opinion that this 
author caused almost universally by his book. ... In order to ruin M. 
Diderot, it has been spread about everywhere that he was the author of all 
the passages in the book of M. Helvetius that revolted people, although this 
philosopher has no connection with the latter, and although they do not 
meet twice a year/ And indeed it is almost certain that Diderot, in spite of 
what his friend Meister later asserted, had nothing to do with the writing 
of Helvetius* famous book. 20 

The accusation that the Encyclopedists found most damaging was the 
allegation that they were closely united in a conscious conspiracy against 
government and religion. This was very frequently alleged, at no time more 
crushingly than when the Attorney General of France solemnly declared in 
1759 before the highest court in the land that It is with grief that we are 
forced to say it, [but] can one conceal from oneself that there is a project 
formed, a Society organized, to propagate materialism, to destroy Religion, 
to inspire a spirit o independence, and to nourish the corruption of 
morals? 1 2I This was but to repeat and summarize the allegations of Palissot 
in his Little Letters on Great Philosophers; 22 of Moreau in his description 
of the Cacouacs; of an Abraham de Chaumeix, whose multi-volumed Legiti 
mate Prejudices against the Encyclopedic, together with an Essay in Refuta 
tion of this Dictionary began to appear in October 1758; of an abbe calling 
himself De Saint-Cyr in his Catechism and Determination of Cases of Con 
science, for the Use of Cacouacs/ 23 This allegation of conspiracy became one 
of the standard myths of the party opposed to the philosophes, as may be 
seen in the Abbe de Barruel s Memoires pour sermr h I histoire du Jaco 
binisms (1797-8) . 24 And it was an allegation that the philosophes always in 
sisted, and rightly insisted, was not so. Grimm denied it, D Alembert denied 
it, although he evidently decided that it was imprudent to publish the manu 
script in which the disclaimer was contained. 25 Even the publishers of the 
Encyclopedic denied it. In their 1758 pamphlet explaining the reasons for the 
suspension of work on the Encyclopedic, they wrote that It is the strictest 
truth [to say] that for the twelve years and more since the Encyclopedic was 


begun, those who co-operate in it have not assembled together one single 
time. Most of them do not know one another. Each one works individually 
on the topic that he has adopted, then he sends his work to one of the Editors, 
without being in communication with the Authors of the other parts/ 26 
That it seemed necessary to make so categorical a statement gives some indi 
cation of how damaging the constant asseveration of conspiracy must have 
been. Yet it must be confessed that the Encyclopedic invited such suspicions, 
for it claimed on the title page of each successive volume to have been written 
by a society of men of letters. 27 

In this atmosphere of increasing tension and foreboding crisis, Diderot 
put the final touches on his play, Le Pere de jamille. It had been a long time 
in the writing. He had announced to the public in the Entretiens sur le Fils 
naturel that Le Pere de famille was being planned. This announcement ap 
peared early in February IJ5J. 2S But Deleyre s letters to Rousseau show that 
Diderot was hard at work on Le Pere de jamille over a year later. 29 Indeed, 
the play with its accompanying Discourse on Dramatic Poetry was not 
actually published until around the beginning of November I758. 30 One of 
the reasons for the long delay was the fact that for a while Diderot gave it up 
in disgust. This is revealed in a letter written on 29 November 1757 to a 
fellow playwright, Antoine Le Bret, who was worried because of rumors 
that the plot of his forthcoming play, Le Faux Genereux, was similar to 
Diderot s. In a hand that showed haste and was, in comparison with the firm 
yet delicate writing customary to him, comparatively illegible, Diderot wrote 
that the plot of his play, of which Le Bret had evidently been previously 
informed, remained unchanged. The first [play] involved me in so many 
vexations that I have been on the point twenty times of abandoning the 
second and throwing into the fire what I have done. My friends have pre 
vented me. I have taken it up again. I have worked at it a little, but so little 
that it is scarcely worth mentioning. I do not foresee that it can be printed 
for two months; the printing will take up another one. 31 Le Bret s play 
had its premiere on 18 January 1758, but ten months passed before Diderot s 
play was published. 

Diderot dedicated his play to an Exalted Personage, a Sovereign. Not a 
very important sovereign, it is true, but still a sovereign. This was not his 
usual way of doing things. Perhaps he did so because he felt his position 
weakened and needed to boast the support of an august name. Perhaps it 
was no more than the influence upon him of Grimm, a man who, as some 
one has remarked, by dint of great efforts finally promoted himself from the 
rank of foremost critic in Europe to that of third-rate diplomat. Diderot s 


letter was addressed to Her Serene Highness the Princess of Nassau-Saar- 
brack, and concerned the problem of how to educate her children * Diderot 
did not meet the Princess until 1765** He submitted his dedication to her 
through the good offices of Grimm sometime before mid-June 1758, and 
apparently without having previously broached the subject. The lady ac 
cepted gratefully after all, she was not a very great sovereign in a some 
what tremulous shimmer of graceful eighteenth-century rhetoric. 33 

Diderot s dedicatory letter is mainly an exhortation to virtue, and has about 
it the sooty smell of an academic showpiece, even though Voltaire said he 
regarded it as a masterpiece of eloquence. 34 Yet Diderot could not touch a 
subject without leaving the imprint of his personality. It is interesting to see 
that he does not truckle or fawn. Indeed, putting into the mouth of the 
Princess the sentiments that he holds and that he professes to believe that 
she, too, holds, he says, I desire that they [the Princess* children] see poverty, 
in order that they be sensitive to it and in order that they know from their 
own experience that they are surrounded by men like themselves, perhaps 
more essential than they themselves, who scarcely have straw to lie on and 
who have no bread/ In view of the fact that Rousseau thought that man was 
good in the state of nature, it is of importance in understanding Diderot s 
outlook upon politics that in this letter he spoke critically of man in the 
state of nature, calling him imbecile and savage. Moreover, he declared that 
men would have no need of being governed if they were not bad. Remember, 
Diderot thinks the Princess should tell her children, power does not give 
peace of mind, and labor does not take it away. . . . Virtue is the only 
habit that you can contract without fear of the future. Sooner or later all the 
others become importunate. 35 

The manuscript draft of the dedicatory epistle contained a passage that 
the Princess particularly and urgently desired suppressed. It is easy to see 
why. For Diderot had put into her mouth the following words, addressed 
to her children: 1 shall take very good care not to speak ill of sensual pleasure 
and not to decry its allure. Its purpose is too august and too universal. I shall 
speak to you about it as if nature herself were listening. Wouldn t she have 
the right to reply to whoever should speak ill of sensual delight, "Be silent, 
foolish one! Do you think that your father would have concerned himself 
with your birth, that your mother would have risked her life to give you 
yours, were it not for the unutterable charm that I have linked to their cm- 
braces? It was pleasure that brought you forth out of nothing." * Even for the 
eighteenth century, this was a little strong. 36 

* There is an English translation, Concerning the Education of a Prince, cd. John M. S. Allison 
(New Haven, 1941). 


In October o 1758 the Pere de famille was in the process of being printed 
and Diderot was extremely impatient to get it off the press. Dr. Lavirotte, 
Regent o the Faculty of Medicine and a friend of Diderot as well as the 
author of the article Docteur en Medecine in the Encyclopedic, was the 
censor assigned by Malesherbes. 37 I wanted to send both one and the other 
[the play and the supplementary "Discourse on Dramatic Poetry"] to M. de 
Malesherbes/ Lavirotte reported, but M. Diderot hurried me so much and is 
so impatient to see his work printed that he carried it away right out of 
hand. 38 Malesherbes evidently informed Lavirotte that some changes would 
have to be made in both the play and its accompanying essay before they 
would be allowed to appear. Somewhat plaintively he wrote to the censor 
that apparently Diderot could not write even an essay on dramatics without 
mentioning government and religion in two or three places. 39 Nor did 
Lavirotte think it would be easy to persuade Diderot to make changes: 1 
merely wish to beg you to observe that no one will have enough authority 
over the mind of M. Diderot to persuade him regarding these suppressions 
and alterations. He will resign himself to them only as a result of the most 
categorical orders. 40 

Diderot did make some changes, though very reluctantly. Here are the 
cartons [substitute pages, to be tipped into volumes already printed and 
bound] that you have required. The things that have offended you have 
been suppressed and those that appeared harsh to you, softened/ 41 But 
Diderot tried to save from the blue pencil a passage occurring in the second 
act, where the Father of the Family recalls the prayer he prayed when his 
son was born. Malesherbes objected to Diderot s reference to God, on the 
grounds that people would regard it as hypocritical. How can you make out 
that I shall be accused of hypocrisy? I am no more the Father of the Family 
than I am the Commander; and if one has me in mind when reading me, 
then the piece must be poor indeed. * 2 Apparently Diderot was able to per 
suade Malesherbes to let the passage stand. It reads as follows: My son, it 
will soon be twenty years since I bathed you with the first tears you caused 
me to shed. My heart leaped up as I saw in you a friend given me by nature. 
I received you into my arms from the bosom of your mother, and, raising 
you toward Heaven and mingling my voice with your cries, I said to God, 
"O God! who have granted me this child, if I fail in the cares You have laid 
upon me this day, or if he is not destined to respond to them, have no regard 
for the gladness of his mother, but take him back." 4S 

The altercation regarding the prayer caused in Diderot a considerable 
effusion of temperament. I saw the man last evening at the Marquis de 
Croismare s, wrote Lavirotte to Malesherbes, probably about 19 October. 


<He was in such a violent fit of despair that we feared lest he throw himself 
out of the window/ 44 And Diderot s letter to Malesherbes, dated 20 October, 
bears the marks of strong emotion: 

This prayer rings true. It is simple. It is moving. It is well placed. This is the opinion 
of M. de Saint Lambert. It is that of M. d Argental The latter was moved by it 
and the former told me that one does not conceive of such effects unless one has 
genius. I admit, Monsieur, that friendship for me has made them excessive in 
their praise. But I have tested this passage on other persons. My wife is a good 
woman who lacks neither common sense nor taste, and it has given her pleas 


deign to consider my situation. Observe that for ten years, for thirty, I 
drink bitterness in a cup never empty. You do not know, Monsieur, how un 
fortunate my life has been. I have suffered, I think, all that it pleases destiny to 
make us suffer, and I was born with a sensitivity out of the ordinary. The present 
misfortune brings to mind misfortune in the past. One s heart swells. One s char 
acter grows embittered, and one says and does foolish things. If that has happened 
to me, I ask a thousand pardons. 48 

As Diderot was finishing his letter, his publisher brought news that Males- 
herbes was assigning a new censor to the job. This was even worse, wrote 
Diderot, for the new man would inevitably demand new changes, which 
meant new cartons, all at Diderot s expense. Monsieur, have the goodness to 
revoke an order injurious to a censor whom you esteem and which will be 
ruinous for me. ... Monsieur, do not ruin me ... do not destroy me.* 4e 
Nevertheless, Malesherbes sent the book not to one new censor but to two. 41 
Censors, however, were becoming exceedingly shy, very conscious of the 
calamities overtaking the unfortunate censor of the book by Helvetius, on 
the one hand, or the sort of browbeating they were likely to get from the 
philosophes, on the other. One of the censors appointed by Malesherbes 
begged off for the first reason. 48 The second censor, a man named Bonamy, 
wrote on 29 October, I shall inform the publisher that I have had the honor 
of sending the work back to you, as being beyond my strength and my 
enlightenment to pass judgment on, which I confess to being true. But as I 
ask only for peace and comfort, and as I do not wish to have a quarrel with 
people who imagine themselves the sole possessors of all human reason, I dare 
to flatter myself that you will keep the word that you had the kindness to 
give me that you would not compromise me with them, for I am apprehen 
sive of them as much as I am of the theologians. 4S Apparently, after all this 
turmoil, Malesherbes was fain to let Lc Pere de famille be published without 
further change. In spite of the censorship Diderot had had his own way. 


Not long after this display of temperament, Diderot had another adventure 
with the office of the director of publications. This was a real mystery story, 
and still remains so to a large degree the Affair of the Dedications. Males- 
herbes referred to it as the most annoying and displeasing of his whole 
administration, and clearly the culprit would have been severely punished 
had Malesherbes been sure who was guilty of the hoax. 50 The facts are 
these: There had been timed to appear just after the publication of Lc Pert 
de famille two of Goldoni s plays, anonymously translated by two of Dide 
rot s friends. // Vero Amico t the play that it was alleged Diderot had plagiar 
ized, was translated by Forbonnais, the man who had contributed to the 
Encyclopedic the admired articles on business and commercial transactions. 
// Padre di famiglia was translated by Deleyre, the young journalist who in 
this same year had tried so hard to reconcile Diderot and Rousseau. These 
translations usually bound together in one volume, if they can be found 
at all, so rare have they become bear up creditably in a collation with the 
original. They are faithful and idiomatic. Nothing in the originals is sup 
pressed, although not infrequently lines are added, especially to serve as 
transitions between scenes. No effort at all, however, was made to tamper 
with // Vero Amico in any way favorable to Diderot. As for II Padre di 
famiglia, it is so far removed in everything but name from Le Pere de famille 
that there could be no question of borrowing. 

These plays, when they were published, purported to be printed at Avignon 
and to be on sale at Liege at Etienne Bleichnarr s. There was no Etienne 
Bleichnarr. The name means in German pale fool, of which the equivalent 
in French is pale sot Thus the word Bleichnarr* turned out to be simply a 
pun on the name of Palissot, the bitter enemy of the Encyclopedists and the 
author of Little Letters on Great Philosophers! In addition, each play carried 
as epigraph a long and puzzling Latin quotation and a dedication, one to 
the Comtesse de * * * and the other to the Princesse de ***** * 5 in 
flowery, insinuating, ambiguous, and probably insulting language. 51 Almost 
as soon as the plays were published, complaints were lodged with Malesherbes 
by two ladies of high position who happened to be well known as enemies 
of the philosophes. The Comtesse de La Marck, who by birth was a Noailles, 
claimed to be the person designated by the dedication in Le Veritable Ami; 
the Princesse de Robecq (who was the daughter of the Marshal of Luxem 
bourg and had recently been the mistress of the Duke of Choiseul) by the 
dedication of the translation of // Padre di famiglia. 

In the code of eighteenth-century French manners, unfavorable personal 
allusions in the press or on the stage were regarded as a grave affront, no 


matter how veiled or slight. This was one of the indirect consequences of 
censorship. For everyone supposed that such attacks, if allowed publication, 
were tacitly approved by the government. Consequently all such situations 
became a matter of face. Someone lost it, and a struggle would develop to 
see which party enjoyed the greater public credit in the effort to get it back. 
This was the reason why D Alembert consistently showed himself very 
touchy about allusions in the press that one is tempted to think it would have 
been wiser to ignore. And in this instance, in conformity with this social 
code, Malesherbes took a grim view of the incident of the dedications and 
started a determined investigation to discover who had written them and was 
responsible for their publication. 

Malesherbes quickly satisfied himself of the innocence of the translators, 
Forbonnais and Deleyre. The trail next led to Diderot, who had had the 
manuscripts of the translations for some days, but who insisted that there 
were no dedications either when they came into his hands or when they 
left them. 52 The Comtesse de La Marck had supposed Diderot to be the 
guilty one D Hemery noted in his journal that she was in a frightful 
rage against Diderot. 53 Diderot called upon her, and managed somehow to 
placate her. Perhaps it was that gifted tongue of his. Probably, though, it 
required something more substantial, for according to Palissot s account of 
the matter to Voltaire, Mme de La Marck secured a signed confession from 
Diderot. 54 Then Mme de La Marck, in a letter to Malesherbes quite charm 
ing in its phonetic orthography, so revelatory of the well-bred illiteracy of 
the upper classes, informed him that she was satisfied and that Mme de 
Robecq and she desired him to carry the matter no further. 55 

Malesherbes reply pointed out that a legal offense had been committed, as 
well as some moral ones: a premeditated attempt had been made to deceive 
him, the responsible magistrate, and to make innocent persons, namely 
Deleyre and Forbonnais, seem guilty. So, Madame, I beg of you to have 
these authors [of the dedications] informed, since they have made them 
selves known to you, that all they have to do is to make their confession 
likewise to me, and I promise you that they shall suffer from me nothing 
more than the disesteem that their manner of acting necessarily brings in its 
train/ But if they did not confess to him, he would put the affair into the 
hands of the Lieutenant-General of Police. 50 

At this juncture Forbonnais wrote Malesherbes insisting that someone 
must make public and explicit acknowledgment of personal responsibility 
for the translations in their entirety. Otherwise, he wrote, he and Deleyre 
would be unjustly suspected of being responsible for the dedications. If this 


was not done, he and Deleyre would resort to the law, and the affair would 
become a public scandal 57 Forbonnais went on to say that witnesses had 
seen a lackey in Grimm s service leaving a copy of the published translations 
at the door of Forbonnais* lodgings. 

The protest from Forbonnais caused Malesherbes to write to the Comtesse 
de La Marck again. It is you, Madame, who brought M. Diderot to his 
senses, first out of fear and then out of admiration and gratitude for the 
nobility of your way of acting. Malesherbes explained the difficulty with 
Forbonnais, and strongly implied that the Comtesse was the only person in a 
position to assure that Forbonnais be satisfied. 58 Evidently Malesherbes was 
hinting that she should persuade Diderot to take the public responsibility. At 
all events, this is what Diderot did, whether Mme de La Marck persuaded 
him or Forbonnais did. It was the latter who forwarded to Malesherbes the 
copy of a letter that Forbonnais had drafted and Diderot had signed. 59 And 
in due time there appeared in the November issue of the Observateur Lit- 
teraire and the December issue of the Mercure de France the following 

Ill-informed persons, Monsieur, having spread about that the published trans 
lation of Le Pere de jamille of Goldoni was done by M. Deleyre and that of 
Lc Veritable Ami by M. de Forbonnais, the knowledge that I have of these two 
plays obliges me to declare that [the translations] just published arc very different, 
and it is established that neither the one nor the other had a part in the printing 
and publication of these works. 

I have the honor, etc., 
Paris, 21 November 1758 Diderot * 

It will be noticed that Diderot, although he absolves Deleyre and Forbon 
nais, does not hint as to who was guilty. The hostile Palissot assured Voltaire 
that it was Diderot himself, but Voltaire replied that he could not believe 
it. 61 Grimm, commenting on Voltaire s letter, told his correspondents that 
D Argental, investigating the matter for Voltaire, had been informed by 
Mme de La Marck that she had had the signed confession in her hand, that 
she had immediately burned it, and that the secret of who it was would die 
with her. 62 Certainly the affair had an air of mystery about it to the end. 
Malesherbes wrote to the Lieutenant-General of Police over a year later, This 
affair remains unpunished for lack of proof, and added that the guilty parties 
were under strong suspicion but yet were not known with certainty. 63 

In fact, however, Grimm was the guilty one. The German pun on the name 
of Palissot, the lackey delivering a copy of the translations at Forbonnais 


lodgings, pointed toward him. And A. A. Barbier, an early nineteenth-century 
literary antiquarian, asserted that Grimm was the author, that Diderot took 
the guilt upon himself, that the offended ladies soon learned that this was 
what Diderot had done, and that the affair had had no other consequences. 64 
But all this remained a little conjectural until the recent discovery and pub 
lication of a letter from Diderot to Grimm written over twenty years after 
the incident had occurred. Diderot s letter permits no doubt that Grimm was 
the real author of the dedications. 65 

Why, then, did Diderot take the guilt upon himself? It is possible that this 
was a really heroic decision. Yet, in what was obviously an extremely com 
plex situation, one can only speculate as to what were his motives. Perhaps one 
of his reasons was that his friend Grimm was a foreigner and might have 
had extremely harsh treatment meted out to him, such as deportation, which 
in Grimm s case would have been calamitous both professionally and per 
sonally. We should like to suppose that Diderot s conduct was simply the 
result of courageous generosity, but in view of the innumerable and varied 
pressures that must have been playing upon him in this emergency, it is 
impossible to say with assurance just why he acted the way he did. 

Still another question must be asked, a very grave one indeed. How guilty 
was Diderot, from the point of view of the probity he was always talking 
about? Unknowingly involved in this intrigue were two men whom Diderot 
knew to be innocent, two men who thought of themselves as Diderot s 
friends. Did Diderot connive at attempting to make them seem responsible 
for having written the dedications? Even though he was protecting his 
friend Grimm, Diderot incurred some moral guilt in this respect, because it 
is a matter of record that only under pressure did he exculpate Forbonnais 
and Deleyre. It may have been, therefore, to this incident that Deleyre was 
referring when in a letter to Rousseau he spoke of having discovered a knave 
among the philosophers and of having been made his dupe. 66 Diderot s con 
duct certainly seems to have been ambiguous perhaps it was laudable, per 
haps it was culpable. Perhaps for he was a man given to subtle rationaliza 
tions when cases of conscience were involved he here revealed that his early 
moral training had been in the hands of the Jesuits, men who had long been 
accused of flagrant sophistry in such matters. 67 Diderot often showed in his 
writings and letters his awareness of life s real and constant ambiguities, 
ambiguities of conduct as well as ambiguities of thought. In fact, he wrote 
his liveliest play upon this very theme. In this piece the hero, Hardouin, is 
a picture of Diderot as Diderot conceived of himself, an affable and obliging 
man who, from the best of motives, involves himself in the most dubious 


and ambiguous conduct. In the final scene the question is asked that gives the 
name to the play: Is he good? Is he bad? And Diderot-Hardouin replies, 
Alternately.* Similarly, one can ask the same question regarding the part 
Diderot played in the affair of the dedications: Est-il bon? Est-il mechant? 
Perhaps the answer is the same. 


Le Pere de Famille and the 
Discourse on Dramatic Poetry 

E-CE his Fils naturelj Diderot s Pere de jamille did 
not immediately receive the honors o a produc 
tion at the Comedie-Franjaise. This had to wait until 1761, but meanwhile 
the play quickly became a widely read and influential book. Between 1758 
and 1800 there were thirty-two editions of it published in French; ten in 
German; three in English, plus a play by Gentleman Johnny Burgoyne more 
strongly influenced by Diderot than the General wished to acknowledge; 
three in Dutch; two each in Russian, Danish, Polish, and Italian; and one 
in Spanish. 1 Many of these editions, especially the ones in French, also con 
tained the accompanying Discourse on Dramatic Poetry/ so that Diderot s 
ideas on the theater, expressed in this book as well as in the preceding 
Entretiens sur le Fils naturel, may safely be said to have reached a wide 

To ancien regime society it seemed self-evident that one of the principal 
preoccupations of a father was to secure suitable matrimonial arrangements 
for his children, and the two main pivots in this new play, as Diderot him 
self pointed out, were to be the establishment in marriage of the Father of 
the Family s two children. 2 Diderot had already stated, in his Entretiens sur 
le Fils naturel, his conviction that the theater should concern itself with the 
points of view and behaviorisms of people s professional and family relation 
ships the judge, the businessman, the man of letters, the father of a family. 
The father of a family! What a subject! he cried. 3 Le Pere de famille, there 
fore, was a play in which parental prudence came into violent conflict with 
the impetuosity of a young lover. Its plot greatly resembled the real-life 
circumstances of Diderot s courtship of Anne-Toinette Champion, even to 
the use of a lettre de cachet. Interesting as such a play was to the eighteenth- 



century public, it is even more interesting to a person studying Diderot s life, 
for it is evident that the Father of the Family is Diderot s own; that Saint- 
Albin, the spirited young lover, is Diderot s recollection of himself; that the 
peevish and hateful Commander, the brother-in-law of the Father of the 
Family and therefore the uncle of Saint-Albin and Cecile, is Diderot s con 
ception of the character of his younger brother, the Abbe; 4 that Cecile, the 
daughter of the family, a composite of loftiness of character, vivacity, re 
serve, and sensitivity,* is Diderot s idea of the character of his sister; 5 and 
that the heroine (whose name is Sophie and not Anne-Toinette) is probably 
Diderot s picture of what he supposed Sophie Volland to have been like when 
she was young. 6 Certainly the characterization of the part suggests that 
Diderot had Sophie Volland rather than his wife in mind when he wrote it. 
If so, Diderot consciously or unconsciously gave Mme Diderot the slight 
of transferring his mistress character and his mistress name to a role that 
his wife had played with him in real life. It is not very surprising that Mme 
Diderot did not go to see the play until its revival in 1769, nor did she go 
very eagerly even then, to her husband s annoyance. 7 

Still another interesting aspect of this play about family life is that no 
living mother nor wife figures in it. The Father of the Family is a widower. 
Now and again Diderot s characters refer with affection to the mother, but 
her absence is by no means essential to the plot. Therefore it is evident that 
Diderot felt unwilling or unable to deal adequately with this character in 
his play. Surely a psychiatrist could speculate very interestingly upon the 
biographical significance of Diderot s leaving the mother out of a play, the 
whole concern of which is with family relationships. 8 

The action takes place within the duration of twenty-four hours in the 
house of M. d Orbesson, the Father of the Family. Saint-Albin, the son, has 
taken of late to staying out at night, and the family is revealed, as the curtain 
goes up, awaiting his return. After these characters have got the play started, 
they retire for the night, leaving the Father of the Family alone. Saint-Albin 
presently enters, dressed as an artisan, and explains that he has fallen in love 
with a virtuous young woman who supposes him to be a workingman. 
Sophie, temporarily stranded in Paris, is attempting to earn enough money 
by spinning to enable her to return home. Entreated by Saint-Albin, the Father 
of the Family consents to see her. 

The Father finds the young lady attractive, but not of a sufficient fortune 
or social standing to be suitable for his son. He therefore offers to provide 
for her return if she will give up Saint-Albin. A very stormy scene ensues 
between the son and the father (who ends by pronouncing his malediction), 

3 2 4 

and between the son and the uncle. The son resolves to kidnap his beloved, 
while the disapproving old Commander decides to secure a lettre de cachet 
that will get her out of the way. Many alarms and excursions follow, through 
the rest of the five acts, and the reader is likely to agree more than once 
with Freron, who wrote that At every instant one feels the quandary he 
[Diderot] is in to stretch his play out. He imitates those unscrupulous manu 
facturers who pull their cloth violently in order to give it greater length at 
the expense of its quality. 9 The play might even yet be unsatisfactorily re 
solved had it not turned out, by the greatest of coincidences, that the Com 
mander is also Sophie s uncle! This revelation, a deus ex machina almost 
identical with the one in Le Fils naturel, establishes the fact that Sophie is 
of good family obviously! for she is her lover s first cousin so that all 
ends happily, save that the gruff and cantankerous Commander remains un 
yielding, unrepentant, and in character to the very end. 

In accordance with the principles of playwriting that Diderot had already 
enunciated in his Entretiens sur le Fils naturel, Le Pere de jamille contained 
elaborate tableaux, quite in the fashion of Greuze, such as the scene at the 
beginning of the second act that portrays the Father of the Family s philan 
thropy, and the scene ending the play. Also included in the script were 
detailed descriptions of scene decoration and indications of stage business, 
and the speeches of the actors were often written in disjointed prose and 
unfinished sentences in order to indicate the use of gestures or the effect 
of strong passions. Frequently these speeches have a telling effect. Saint- 
Albin, especially, speaks the authentic language of an impulsive and mer 
curial young man overwhelmingly in love. Moreover, he speaks the lan 
guage of a man who is purified by the experience. This accent upon the 
virtuousness of romantic love, preceding Rousseau s Nouvelle Helo ise by 
two years, represented something new and compelling in the French theater 
and shows that a subtle change was at work in the mores of the age. 10 You 
don t know what I owe to Sophie, you don t know. . . . She has changed 
me, I am no longer what I was. . . . And when the worldly Commander 
asks Saint-Albin what he thinks he is going to live on, the latter replies with 
bright confidence, as though it were all the wealth of the Indies, 1 have 
fifteen hundred livres a year!* 11 The eighteenth century liked that. 

Like Lucifer in Paradise Lost, the most absorbing character in the whole 
play is one who was scarcely meant to be so. This is the Commander, and it 
is a good touch to leave him to the very end unconciliatory and unreconciled. 
The Father of the Family, on the other hand, does not fill the role intended 
for him. He is too passive. He follows the action instead of dominating it. 


Although Le Pere de famille was a quite interesting play regarding a com 
plicated tale of love, it was far from demonstrating what Diderot thought 
it demonstrated: the peculiar point of view of paternal relationship. To show 
that, he would have had to make his father of the family a much more 
positive and dynamic character, and much more in conflict with himself. 12 

Diderot was, however, proud of his plot, and declared that he had written 
it straight through, the first scene first and the last scene last. 13 While he 
was constructing it, he wrote to an acquaintance who had hinted that the 
plan of the work could be recontrived if necessary, This plot is sewn in such 
a manner, this framework is assembled in such a fashion, that I would not 
be able to rip a stitch or misplace a peg without the whole thing s collaps 
ing/ 14 The complications in the play are symbolized by the fact that the 
synopsis of it in a standard contemporary dictionary of the theater ran to 
three tightly packed pages. 15 But in spite of its involutions, Diderot was in 
genuously pleased with his plot he admired it through several pages of 
his accompanying Discourse on Dramatic Poetry especially because he 
regarded it as psychologically sound and as having the proper sort of in 
evitability and inexorability about it. 16 Not every critic has agreed with him. 17 

By a passing allusion to an incident in which Saint-Albin had figured 
during the siege of Port Mahon, Diderot increased the feeling of contempo 
raneity in Le Pere de famille. This made his references to such matters as 
convents and lettres de cachet all the more topical and daring. When Cecilc 
declares her intention of entering a convent, the Father of the Family refuses 
to allow her to descend into a living tomb : Nature, by according you social 
qualities, did not destine you to uselessness. Even more bold was Diderot s 
making the lettre de cachet the villain of the piece. Perhaps he remembered 
the villainous role a lettre de cachet had played in his own courtship. At all 
events, this instrument of the king s will was not used in Diderot s play, 
as it had been in Moliere s Tartuffe, to make the play come out happily; to 
the contrary, it was only by 7202 using the lettre de cachet that a happy 
denouement was reached. To imply that an exercise of the king s will would 
be equivalent to calamity was daring indeed. Moreover, Diderot insinuated 
that lettres de cachet were purchasable, and for reasons of private vengeance. 
For he has the Commander say of Cecile s maid, a person whom the Com 
mander heartily dislikes, But I have overlooked one thing. The name of this 
Clairet would have done very well on my lettre de cachet, and it wouldn t 
have cost any more. 18 Could Dickens be more pointed? When the play was 
finally produced, these lines were not spoken. The censor Bonamy had re 
marked to Malesherbes that it was none of Diderot s business either to praise 


or to blame lettres de cachet Nevertheless the book was printed as Diderot 
had written it. 

Diderot presented Voltaire with a copy of Le Fils naturel and, a year later, 
of Le Pere de famille. In each case Voltaire was plainly embarrassed as to 
how to reply. The tactics he used in acknowledging the first evidently seemed 
to him successful enough to bear a second trial, for the letter of thanks for 
the second was extremely like its elder sister. Voltaire s formula was a simple 
one. It consisted of praising the author rather than the author s play. The 
work you sent me, Monsieur, he wrote in regard to Le Fils naturel resem 
bles its author; it appears to me to be full of virtues, sensitivity, and philoso 
phy. Like you, I think that there is much to be reformed in the theater at 
Paris. ... I exhort you to diffuse in the Encyclopedic, as much as you are 
able, the noble freedom of your soul/ 20 Acknowledging in its turn Le Pere 
de famille, Voltaire wrote that it contained tender and virtuous things, in a 
new style, as with everything you write. Then he hurriedly changed the 
subject to the Encyclopedic. Tou deserved to be better seconded,* he wrote, 
which was a very significant thing to say only six months after D Alembert s 
desertion. 21 That Voltaire had no high opinion of Le Pere de famille, how 
ever, is proved by his letter to Mme du Deffand regarding it. Have you 
had Le Pere de famille read to you? Isn t it ludicrous? In faith, our century 
is a poor one compared to that of Louis XIV. 22 

It might seem odd, since Le Pere de famille was written in prose, that 
Diderot should entitle the little book accompanying it a Discourse on 
Dramatic Poetry/ He used the word poesie, however, in the figurative sense 
of signifying all that is lofty and touching in a work of art. 23 In his several 
chapters Diderot dealt with such subjects as plot, dialogue, incident, the dif 
ferent kinds of plays, characterization, division of a play into acts and scenes, 
stage decoration, costumes, pantomime and gestures, and, most important of 
all, the social function of the theater. In illustrating his points he exhibited 
a broad command of classic and modern authors. Of course he had much to 
say about Corneille, Racine, Moliere, and Voltaire, and he punctuated his 
discourse with allusions to Boileau, Fenelon, La Rochefoucauld, the Abbe 
Prevost, Buffon, and even, in spite of the censor s warning, to Helvetius. 24 
He also referred to Aristotle, Plato, Homer, Euripides, Sophocles, Aristoph 
anes, Plautus, Anacreon, Catullus, Lucretius, Horace, Shakespeare, George 
Lillo (author of The London Merchant, or The History of George Barn- 
wclT), and Samuel Richardson of current Pamela-Clarissa fame. The author 
whom he relied upon most, however, as providing models for his own type 
of play, was Terence. 25 Diderot was again at pains to show that his drame 
was really as old as Terence and yet as new as Le Pere de famille. 


Diderot s proposals for reform in the theater were inspired by his out 
spoken conviction that almost everything about current play production rang 
false. In reply to some criticisms o his Discourse on Dramatic Poetry that 
a well-known actress and novelist of the day, Mme Riccoboni, had sent to 
him,^ Diderot remarked, Indeed, my friend, I have not been to the theater 
ten times in fifteen years. The falseness of everything done there is unendur 
able to me/ 26 

Diderot had a point. Much in the acting and play production of the day 
was needlessly conventional and artificial. There was more emphasis upon 
declaiming than upon acting. Diderot accused the actors of his day of acting 
with the face only, not with the whole body, and cited Garrick as the example 
they should emulate. 27 To correct the mannerisms of actors, Diderot favored 
rehearsals in an arena before a critical audience, a suggestion which entitles 
him, some people think, to be considered as the inventor of theater-in-the- 
round. Then, too, actors dressed magnificently and irrelevantly, with no 
regard to the nature of their parts. 28 Diderot believed in a greater co-ordina 
tion of the various theatrical arts than was customary. For example, he 
emphasized scenic effects, to be achieved in part by the skillful grouping and 
teamwork of the players; he called these effects tableaux, having in mind what 
a modern director would probably call dynamics. 29 Furthermore, he in 
sisted that the painting of stage scenery required a greater rigor and fidelity 
to truth than any other kind of painting. 30 All this implied, as a great student 
of French literature has remarked, the complete reformation of theatrical 
production. Every improvement in the art of production for the past 150 
years has sprung from Diderot, and the innovators of today still take their 
rise from him, even when they deny it. 31 

When Diderot wrote, the performances of the Comedie-Franfaise were 
still much impaired by the presence of spectators on the stage itself. Even the 
best actors were hampered by this practice, for scarcely anything could be 
conceived more apt to destroy the illusion of the theater. The custom was a 
source of income to the company of the Comedie-Francaise, however, al 
though everyone suffered from having to make entrances and exits while 
dodging around some count or marquis engaged in his own distracting con 
versation. Diderot remarked in his letter to Mme Riccoboni that no one 
should be allowed on the stage: then improvements could be brought about 
at once in scene decoration. 32 As it happened, this particular reform, which 
marked the end of an epoch in the French theater, was about to be accom 
plished. Thanks to a substantial endowment given by a Comte de Lauraguais, 
the company of the Comedie-Francaise agreed thenceforth to forego the 
revenue accruing from selling places on the stage. Dating from the Easter 


vacation of 1759, spectators were banished from the stage of the Comedie- 
Frangaise. 33 

The Discourse on Dramatic Poetry was a flavorsome essay because Diderot 
injected a great deal of his own personality into it.* For example, not only 
was the whole work dedicated To my friend, Monsieur Grimm/ but Diderot 
also wrote in the body of the work, One should always have virtue and 
virtuous people in mind when one writes. It is you, my friend, whom I in 
voke when I take up my pen; it is you whom I have before my eyes when 
I do anything. It is Sophie whom I desire to please. If you have smiled upon 
me, if she has shed a tear, if both of you love me more than ever, I am 
recompensed. 34 As one biographer of Diderot has remarked, it is only in 
the eighteenth century that a situation like this would be likely to occur: 
a married man s unmarried mistress and his friend, the bachelor lover of 
another man s wife, are invoked as the twin inspirations of a play, the purpose 
of which is to glorify the family. 35 

Diderot was led into making the Discourse on Dramatic Poetry* a very 
personal book by the nature of his argument. Because I am what I am, he 
said in effect, I write the kind of plays that I do. Naturally, this line of 
thought made it necessary for him to tell the reader what sort of person he 
was, and one finds in the essay a number of pen portraits of the author as 
he seemed to himself. Now, of course, Diderot not only thought that he was 
as he described himself, but he also thought, quite obviously, that it would be 
well for others if they resembled him as much as possible. Doubtless this is a 
method of literary criticism that egotists find congenial and yet, when used 
by a great temperament of Diderot s range and depth, it cannot be con 
demned as simply fatuous. Diderot s views, subjective as they are, were 
extremely influential, and he has been called, quite rightly, not merely an 
author but a legislator. 36 To give some idea of how seriously Diderot s ideas 
were taken, it is apposite to recall that Lessing, the anonymous translator into 
German of Diderot s plays and dramatic essays (1760), declared in his intro 
duction that I might well say that no more philosophical mind than his has 
occupied itself with the theater since Aristotle. 37 

Diderot conceived of himself as having an upright and straightforward 
character, perhaps a little simple but all the more respectable because of it. 
Born with a sensitive and upright disposition, I confess, my friend, that I 
have never been dismayed by any task from which I could hope to emerge 

* The first five sections of Diderot s Discourse, 1 out of a total of twenty-two, are published 
ic English translation by John Gaywood Linn in Dramatic Essays of the Neo-Classic Age, eds. 
Henry Hitch Adams and Baxter Hathaway (New York, 1950), 349-60. 


successfully through the use of reason and integrity. These are the weapons 
that my parents early taught me to manage: I have so often used them 
against others and against myself! 38 

Although he spoke with gratification of his use of reason, he was equally 
proud of his ability to respond to situations emotionally. This was the sensi 
tivity, the sensibility, that he and most of his biographers have regarded as 
the central and most important characteristic of his personality. 39 This ex 
treme response to the emotional implications of a circumstance is not merely 
one of the most significant phenomena in the personality of Diderot. It is also 
one of the interesting crosscurrents in the Age of Reason, coloring much of 
the literature of the second half of the eighteenth century. 40 Diderot had 
always appreciated the role of emotions in psychological experience, and the 
first apothegm in his Pensees philosofhiques had burst out: People are for 
ever inveighing against the passions ... yet it is only the passions, and grand 
passions, that can lift the soul to great things. And when, in 1758, he analyzed 
his own personality, in reply to an assertion by Mme Riccoboni that he had 
a great deal of wit, he emphasized once again his sensibilite and surprisingly 
denied his wit: *I? One cannot have less. But I have something better: sim 
plicity; sincerity; warmth in the soul; a mind easily kindled; an inclination 
to be enthusiastic; a love for the good, the true, and the beautiful; a disposi 
tion ready to smile, to admire, to become indignant, to sympathize, to weep. 
Furthermore, I know how to be carried beyond myself, a talent without 
which one can do nothing worth while. 41 

When he thought of himself as a philosopher, he liked to think he re 
sembled the ancients. This is apparent in his description of the philosopher, 
Aristes, who is obviously Diderot s conception of himself: *. . . almost the 
only thing that he lacked of an ancient philosopher was the mantle. 42 
Particularly, he thought of himself as having a great deal of the massive 
simplicity, the ruggedness, and starkness of the ancients. Nature has given 
me, he wrote, a taste for simplicity, and I seek to perfect it by reading the 
classics. 43 Thus, by mentioning the ancients, he makes the transition from 
talking about simplicity in himself to talking about simplicity in plays. 

This simplicity he finds in the manners and morals of the ancient peoples, 
against which he contrasts the conventionalities and fussiness of the manners 
(and the plays) of his day. Of course it is easy and true to say of his doc 
trine that his precepts were better than his example. The mountain labored 
and produced a melodrama. But his precepts were, nevertheless, very good. 
By his constant reference to the manners and to the drama of the ancients, 
Diderot hoped to reveal essential insights into the twin mysteries of artistic 


creation and the aesthetic appreciation of it. For he accepted as self-evident 
that the elemental and unsophisticated folkways of the ancients, the simple 
and profound insights of the classic dramatists, could reveal the components 
of genius and clarify for moderns the proper criteria of taste. Much of 
Diderot s Discourse on Dramatic Poetry/ therefore, goes beyond mere 
problems of stagecraft to the deepest and most mysterious sources of creativ 
ity and the appreciation of creativity. One complements the other. The artist 
produces what the spectator appreciates. As Diderot formulated it, one facet 
of the problem was genius, the other was taste; one creation, the other 

As for genius, Diderot had a theory that it exists at all times, but the men 
who possess it remain torpid unless extraordinary events excite the mass and 
cause men of genius to appear. Then feelings accumulate in the breast, 
ferment there, and those who have a voice, feeling impelled, unleash it and 
feel relieved. . . , Poetry demands a certain something of the enormous, the 
barbarous, and the wild. . . . When will poets be born? After a period of 
disasters and great misfortunes, when the harassed peoples commence to 
breathe once more/ 44 Diderot s was a theory of art not unlike that of the 
Romantics; in particular, Victor Hugo. 46 

The mystery of genius fascinated Diderot, and speculation about it often 
recurs in his writings. 46 But he was almost equally interested in discovering 
the proper criteria of taste. Both required the faculty of imagination, of that 
he was sure, for he wrote, Imagination! there s the quality without which 
one cannot be a poet or a philosopher or a man of reason or a man of wit 
or, simply, a man.* 47 In the search for the canons of good taste, Diderot felt 
and hoped that there is a discoverable standard, a rule anterior to every 
thing else. 4S In morals as in the arts/ he added, in his letter to Mme Ric- 
coboni, there is no good or bad as far as I am concerned save that which 
is good or bad at all times and everywhere. I desire that my morality and my 
taste be eternal. ... It is only the true that is of all times and places. 49 

Diderot s mention of morals and arts in the same sentence emphasizes 
once again his utilitarian approach to problems of taste and artistic creation. 
In the last analysis Diderot found the supreme purpose of the playwright to 
consist of combining the moral and the aesthetic. In this view the theater 
becomes a kind of temple for a secular cult, wherein the good man is con 
firmed in his goodness and the bad man given pause. The pit of the theater 
is the only place in which the tears of the virtuous man mingle with those 
of the vicious one. There, the evil man becomes irritated against the very 
injustices he has himself committed, sympathizes with the misfortunes that 


he himself has caused, and grows indignant at a man of his own character. 
But the impression has been made; it lingers in us, in spite of ourselves; 
and the evil man leaves his box less disposed to do evil than if he had been 
scolded by a severe and harsh orator. 50 

Such views are, of course, anathema to those aestheticians who analyze 
art simply in terms of itself, a process described, sometimes with unkind 
intent, as art for art s sake. They were also anathema to the orthodox 
Christians of Diderot s day, who were inclined to be scandalized, as was the 
censor of Lc Pere de famille, at the proposition that the stage could be a 
better vehicle for preaching than the pulpit. 51 Diderot s attitude can be ex 
plained in part by his opposition to Christian morality, in part by his con 
viction of the positive effect the drama had had in ancient times and the 
effect that it still might have in his own day. 

Diderot expected great things from the theater, provided that it was or 
ganized in accordance with principles he deemed correct. Should this be 
done, the theater could offer, in morals as in the arts, standards that are 
eternal. Thus his Discourse on Dramatic Poetry, which might at first 
seem only about how to contrive a plot or decorate a scene, in reality em 
braced some of the greatest and the most abiding themes of the nature of 
genius and the criteria of taste; of the function of the artist; and, most of all, 
of the good, the beautiful, and the true. Nor was this all as if in a work 
on aesthetics this was not enough. For Diderot had, as usual, a passion for 
melioration. His desire for the improvement of conditions, combined with 
his faith in the useful and utilitarian, caused him to hope that the playwright 
could indeed be a sort of legislator/ a Lycurgus magnificently devoting his 
genius to the betterment of his fellow man. Oh! what good would redound 
to men, he wrote, if all the imitative arts would adopt a common purpose 
and one day would co-operate with the laws in making us love virtue and 
hate vice. Such an attitude explains why his book was important in the 
general ferment of eighteenth-century ideas, even though one may contend 
that it was often mistaken. Every people has prejudices to be destroyed, vices 
to be attacked, ridiculous customs to be decried, and every people has need 
of plays, but plays appropriate to it. What a means of preparing for the chang 
ing of a law or the abrogation of a custom, if the government knows how to 
use it! 52 

Thus, at the end, Diderot arrived at the threshold of politics. 


The Death of the Phoenix 

WHILE Diderot the playwright was enjoying in 
the winter of 1785-9 a very considerable suc 
cess, Diderot the Encyclopedist was faring badly. Crisis had become chronic 
in the affairs of the Encyclopedic. D Alembert s resignation had greatly re 
tarded the printing of Volume VIII just as the publication of DC I Esprit 
had created a feeling that the Encyclopedic was an incubator of subversion, 
spawning works like this of Helvetius which in their doctrinaire and in 
elastic psychology implied views about the nature of man and the universe 
profoundly inimical to established religion. Both externally and internally, 
therefore, the well-being of the Encyclopedic had become decidedly precarious 
and, as events were soon to show, the venture was in fact beginning to 
topple over into catastrophe. 

Although the affairs of the Encyclopedic were consequently being carried 
on in an atmosphere of strain and crisis, it does not appear that Diderot 
labored under a sense of impending doom. The Encyclopedic advances, in 
the midst of all sorts and kinds of contradictions, wrote Grimm in his news 
letter for 15 December 1758, and Diderot himself wrote to Turgot in January, 
soliciting articles and announcing, with remarkable optimism, that a new 
volume was about to be published and that the Encyclopedic was being 
reborn. 1 

In reality, the Encyclopedic was at that very moment in the gravest peril. 
Fate now began to rain hammer blows upon Diderot as though he were the 
protagonist overwhelmed, yet tenacious and enduring in some Greek 
tragedy. And perhaps it was with some consciousness of the Hellenic stark- 
ness and grimness of the struggle that he wrote some months later to Grimm, 
Tate, my friend, can change in a moment from good to ill, but not from ill 
to good; and mine is that of being tormented to the very end. He who de 
votes himself to letters sacrifices himself to the Eumenides. They will leave 
him only at the threshold of the tomb. 2 



One of the blackest days in the history of the Encyclopedic was 23 January 
1759, only two days after Diderot s optimistic letter to Turgot. On that day 
the Attorney General, a man named Omer Joly de Fleury, harangued the 
united assembly of magistrates who made up the Parlement of Paris. The 
burden of his indictment was that the kingdom was being jeopardized by 
the poison of impious books, foremost among them the Encyclopedic. With 
the rhetoric, earnestness, and exaggeration customary in this sort of verbal 
exercise, the Attorney General declared that a conspiracy was afoot: 

Society, Religion, and the State present themselves today at the tribunal of justice 
in order to submit their complaints. Their rights have been violated, their laws 
disregarded. Impiety walks with head held high. . . . Humanity shudders, the 
citizenry is alarmed. . . . 

It is with grief that we are forced to say it: can one conceal from oneself that 
there is a project formed, a Society organized, to propagate materialism, to destroy 
Religion, to inspire a spirit of independence, and to nourish the corruption of 
morals? . . . 

In the picture that we have just drawn of the principal maxims of this work 
[De l f Esprit] you are seeing in fact, Messieurs, simply the principles and detestable 
consequences of many other books published earlier, epecially the Encyclopedical 
Dictionary. The book De I Esprit is, as it were, the abridgment of this too-famous 
work, which according to its true purpose should have been the book of all knowl 
edge and has become instead the book of all error. . . . 3 

Inasmuch as Helvetius had already made a solemn retraction, a fact which 
Joly de Fleury announced in his harangue, the weight of the Attorney 
General s attack obviously rested upon the Encyclopedic. In addition, the 
unrepentant Diderot was a special target of the indictment, shown by the 
fact that Joly de Fleury had included in his original draft of offending books, 
to be mentioned by name, not only the Pensees philosophiques but also the 
Letter on the Blind, the Letter on the Deaf and Dumb, and the Thoughts on 
the Interpretation of Nature* The Attorney General also expressed in his 
indictment indignation regarding one of the Encyclopedias most emphasized 
and self-professed characteristics: all the venom rife in this Dictionary is to 

be found in the cross references 5 It is not surprising that he should say 

so, seeing that Diderot s own article on Encyclopedia had ostentatiously 
advertised the ideological use to which the cross references were to be put. 6 
Let it be said in passing, however, that cross references were actually less 
used, and less skillfully used, than they should have been. 7 Even Le Breton 
admitted this, when replying in 1768 to an upstart proposal that the Ency- 



clopedie should be completely redone. 8 Whether as a result of the pressure 
o time or of simple negligence, the system of cross references did not turn 
out to be so elaborate or insidious as Diderot had said it would. But Joly de 
Fleury is hardly to be blamed for taking Diderot at his word. 

Responding to the Attorney General s indictment, the Parlement of Paris 
decreed that the sale and distribution of the Encyclopedic should be sus 
pended, pending an examination of the volumes already published. 9 And on 
6 February the membership of the examining commission was announced. 10 
Three doctors of theology, three lawyers, two professors of philosophy, and 
one academician: nine men, and good Jansenists all. 11 

Joly de Fleury s indictment and the resultant action of the Parlement 
were a testimonial to the influence and effectiveness of the Jansenist De 
Chaumeix s Prejuges Ugitimes contre I Encyclopedic, a work which kept 
dropping relentlessly from the press, volume after volume, in the years 1758 
and I759. 12 The author of this compilation was not the only tormentor of 
the Encyclopedists there were also Moreau, Palissot, and others more ob 
scure 13 - but at just this juncture he was the most excruciating, and with 
one voice the philosophes exclaimed that he misrepresented their writings or 
grossly quoted them out of context. 14 As the publishers presently wrote to 
Malesherbes, We take the liberty of imploring you not to sacrifice us, as a 
result of impressions unfavorable to the Encyclopedic caused by a writer who, 
in altering the passages he quotes or in presenting them in a false light, has 
passed beyond the limits of judicious criticism. 15 

There can be no doubt that there existed among the devout in 1759 a great 
deal of alarm about the progress of freethinking in France. In so far as this 
was true, the action of the Parlement may be interpreted as sincere. Even 
so, it may have been too zealous for the good of its own cause, for, as Barbier 
remarked, perhaps it would have been prudent not to set forth eloquently, 
in the discourse of the Attorney General, the systems of deism, materialism, 
and irreligion, and the poison that perhaps exists in some of the articles, 
there being many more persons with the capacity of reading this 6 February 
decree of thirty pages than of thumbing through seven folio volumes. 16 

It should also be noticed that the action of the Parlement, sincere though 
it no doubt was, was partly inspired by shrewd political calculation and had 
a certain captiousness about it. As Tom Paine observed in The Rights of 
Man regarding eighteenth-century France, Between the Monarchy, the 
Parliament, and the Church, there was a rivalship of despotism. In this 
instance the action of the Parlement was tantamount to insinuating that the 
regularly constituted offices of administration Malesherbes and his censors, 


operating under the authority of the chancellor, who, in turn, received his 
authority from the king were remiss. Rivalry between Crown and Parle- 
ment was chronic during the eighteenth century, and this incident furnishes 
an excellent example of the Parlement s attempt to encroach upon the power 
of the throne. So, too, did Malesherbes and others interpret it at the time. 17 
From the standpoint of the Encyclopedic, the Parlement forced the issue 
at a particularly touchy moment, for the quinquennial representative assem 
bly of the French clergy was being held in 1758-9. At each of these assemblies 
the clergy voted the government what they meticulously and emphatically 
described as a c free gift (don gratuit), thus symbolizing the clergy s fierce 
resistance to the idea that church property should be taxed as other property 
was, or, indeed, that it should be taxed at all In such circumstances, the 
clergy were usually able to see to it that their free gift really bought some 
thing. Their temper being what it was in 1759 for example, in the preced 
ing year an abbe had actually published a justification of the Massacre of 
St. Bartholomew s Day, as well as a defense of the Revocation of the Edict 
of Nantes* it is fairly safe to conclude that even had the Parlement not 
forced the issue, the government would still have been under pressure to 
do something about the Encyclopedic. The Assembly of the Clergy got what 
it wanted in 1759, and was so well satisfied that, before it dispersed, it voted 
the government an unprecedented sixteen million livres. 18 

The appointment by the Parlement of the nine examiners was not in itself 
a deathblow for the Encyclopedic, although it was very bad news and the 
harbinger of worse. It came just at the time when Volume VIII was in 
press. 19 In spite of this adversity, Diderot, with astonishing perseverance, 
pushed on with plans for continuing the work. A letter written on 12 Feb 
ruary by Nicolas Caroillon of Langres, who was then visiting the Diderots 
in Paris, remarked that M. d Alembert and M. Diderot are going to com 
mence work upon the continuation of the Encyclopedic And on 24 February 
D Alembert wrote, somewhat scornfully, to Voltaire, As for Diderot, he 
continues to be dead set upon wanting to do the Encyclopedic; but it is being 
asserted that the Chancellor does not agree with this way of thinking: he is 
going to suppress the work s license, and give Diderot peace and quiet in spite 
of himself. 20 

The blow fell on 8 March. On that day a royal decree was issued condemn 
ing the Encyclopedic and suppressing it in its entirety. The advantages to 
be derived from a work of this sort, in respect to progress in the arts and 

* Abbe Jean Novi de Caveirac, Apologlc de Louis XIV ct de son Conseil, sur la revocation de 
Vcdit de Nanfef , . , wee une dissertation sur la journee de la S. Earthelemi (n.p., 1758)- 


sciences, the decree declared, can never compensate for the irreparable 
damage that results from it in regard to morality and religion. Thus the 
King, sitting in his council at Versailles, and upon the advice of the Chan 
cellor, revoked the license, claiming to do so for good and all: Besides, what 
soever new precautions might be taken to prevent there creeping into the 
last volumes features as reprehensible as those in the earlier ones, there would 
always be an inherent drawback in allowing the work to continue, namely 
that it would allow of the dissemination not only of the new volumes but also 
of those that have already appeared. 5 21 It was scant comfort to Diderot and 
the publishers that the decree took the matter out of the hands of the Parle- 
ment and the Parlement s nine examiners. 

Diderot s policy had been to transform the Encyclopedic from a mere work 
of reference to a conveyor of ideas ideas that in the last analysis were pro 
foundly political in their effect. He was now paying the price of this daring 
policy; his work had become inextricably entangled among political forces 
vying with one another for power. Nor were old religious animosities un 
stirred. The reference in the royal decree to the advice of the Chancellor 
made Barbier suspect that Lamoignon was aiding his friends the Jesuits to 
forestall the Jansenist Parlement. 22 In all of these rivalries and antipathies 
the Encyclopedic was in part agent, in part scapegoat. No doubt the struggle 
was made more bitter by the irritations and frustrations caused by the failures 
and the disgraces of the French arms in the great war then being waged. 
Diderot was caught in the bufferings of a great and bewildering political 

Still, Diderot and the publishers did not despair. Private property and 
indeed a great deal of it was at stake, and even if the venture could not 
be saved on its intellectual merits, perhaps it could be on its commercial 
ones. The publishers had accepted from their subscribers and there were 
now some four thousand 23 advances of money considerably greater than 
the value of the volumes that had so far been issued. Later in 1759 the gov 
ernment declared this difference to be the not inconsiderable sum of seventy- 
two livres on each subscription. 24 In view of all the capital outlays that the 
publishers had already made in anticipation of being allowed to finish the 
many volumed work, it followed, of course, that if they were required to 
make a refund they might very easily find themselves bankrupt. Just Volume 
VIII alone, the four thousand copies of which were ready to be distributed 
to subscribers but were now forbidden by the royal decree, represented a 
large investment. In present-day prices the total edition of this volume was 
worth some $400,000, if one follows the calculations of a. leading French 


economist and uses for the basis of price comparison the wages of the no 
toriously underpaid, unskilled labor of that day and the wages for unskilled 
labor in ours. 25 In the ancien regime it was always an extremely grave matter 
in the eyes of magistrates to touch private property, and this, of course, con 
stitutes the reason why Diderot and his friends so often talked about the 
immense sums ventured upon the Encyclopedic?* The very starkness of 
their financial outlook may, paradoxically, have caused the publishers to hope 
that the government would stop short of ruthlessly bankrupting them. 

So the publishers and Diderot did not quite despair. Instead, they took two 
important decisions. At a dinner meeting, held probably in late March 
(Diderot described these events in a letter to Grimm on i May), we made 
our arrangements; we encouraged one another; we swore to see the thing 
through; we agreed to work up the following volumes with as much free 
dom of thought as the preceding ones, even at the risk of having to print 
in Holland. . . . But as it was to be feared lest my enemies redouble their 
fury if this arrangement should become known, and persecution, changing 
the object of its attack, be transferred from the book to the authors of the 
book, it was agreed that I should not show myself and that David should 
see to gathering in the parts still lacking/ 2T 

Thus Diderot went underground : the bolts on my door were shot each 
day from six in the morning until two in the afternoon. 2S The Encyclopedic 
was to go on. But clearly it was to be a lonely business. D Alembert could 
at most be counted on for some articles on mathematics, and Diderot told 
Grimm that there was no question of trying to persuade D Alembert to take 
on again any of the duties of an editor. D Alembert had been at the dinner, 
but, according to Diderot, had comported himself outrageously and left 
early. It is certain that the Encyclopedic has no enemy more determined 
than he. 2d No person with any official connection wanted henceforth to be 
associated with a condemned work, so there was no use of counting any more 
on Turgot. Marmontel and Duclos were already gone. The Abbe Morellet 
explained in his Memoir es that The Encyclopedic having been suppressed 
by decree of council, I did not think that I should henceforth share the dis 
credit that this suppression would cast upon a man of my profession who 
should continue to co-operate, in spite of the government, with a work 
proscribed on the grounds of attacking government and religion. 30 Even 
Voltaire, who was safe enough far off at the Genevan frontier, decided to 
make no more contributions. 31 Few colleagues were left to Editor Diderot, 
save the untiring compiler, De Jaucourt and himself. 

Diderot s sense of loneliness was increased during this prolonged nervous 


crisis by the fact that Grimm left Paris in early March to rejoin Mme d Epi- 
nay in Geneva, stopping off at Langres on the way in order to see Diderot s 
old father, who was to live only a few weeks longer. 32 Diderot s letters to 
Grimm contain an abundance of information regarding the events of this 
unhappy year. They are documents, too, that vividly reveal Diderot s state 
of mind, his exhaustion, his irresoluteness, his dejection, his sorrow over the 
death of his father, and his loneliness, which caused him to write to his 
absent friend in terms of a devotion quite feminine and seek to draw 
strength from the superabundance of Grimm s bland and sometimes brutal 


Suddenly Diderot found himself in very real jeopardy of arrest and punish 
ment. His underground routine of writing articles behind bolted doors was 
cataclysmically interrupted by a scare that was anything but imaginary. All 
of a sudden it has been necessary to carry off the manuscripts during the 
night, escape from my own house, sleep elsewhere, seek out a refuge, and 
think of providing myself with a post chaise and of traveling as far as the 
earth would carry me. 33 What had happened was that there was being 
surreptitiously circulated in Paris a pamphlet misleadingly entitled Memo 
randum for Abraham Chaumeix against the Would-be Philosophers Diderot 
and D Alembert, and that its authorship was generally ascribed to Diderot. 34 
He described the pamphlet to Grimm as a long, insipid, boring, and flat 
satire. No lightness, nor finesse, nor gaiety, nor taste, but, in compensation, 
insults, sarcasms, and impieties. Jesus and his mother, Abraham Chaumeix, 
the Court, the city, the Parlement, the Jesuits, the Jansenists, men of letters, 
the nation in a word, all the respectable authorities and all the sacred 
names that there are, dragged in the mud. That s the work being attributed 
to me, and that almost with unanimity. 35 No doubt the pamphlet was 
ascribed to Diderot because Abraham Chaumeix had been such a gadfly of 
the Encyclopedic; but Diderot, in a letter the tone of which seems to reflect 
his awareness of Malesherbes exasperation about the recent Affair of the 
Dedications, swore to Malesherbes on all that men hold most sacred, that I 
had no part in it directly or indirectly. 36 Besides this assurance, Diderot had 
had to visit the Lieutenant-General of Police, the Solicitor General, and the 
Attorney General, in each place protesting his innocence. C I have been over 
whelmed by so much anxiety and so much fatigue, both at once, that I 
shan t get over it for a couple of months. Diderot s acquaintances he 
mentioned specifically D Holbach, Malesherbes, Turgot, D Alembert, and 
Morellet all urged him to take to flight, all of them arguing that in regard 
to a criminal case the safest thing to do was to enter one s plea from afar. 


Yes, the safest, answered Diderot, but the most honest is not to accuse 
oneself when one is innocent/ 37 So he stayed. 

A famous story regarding the relations of Diderot and Malesherbes is told 
by Mme de Vandeul, and almost certainly pertains to this period. Some time 
afterwards [Mme de Vandeul had just been describing Diderot s imprison 
ment at Vincennes], the Encyclopedic was stopped again. M. de Malesherbes 
warned my father the next day he would give the order to seize his manu 
scripts and boxes. 

"What you tell me upsets me horribly. I shall never find the time to move 

out all my manuscripts, and besides it is not easy to find in twenty-four hours 

people willing to take charge of them and with whom they will be in safety." 

"Send them all to me," replied M. de Malesherbes, "No one will come 

here to look for them." 

My father did indeed send half of his papers to the very man who was 
ordering the search for them. 38 The usual presumption has been, following 
the context of Mme de Vandeul s account, that this event occurred in 1752, 
when the first two volumes were suspended. But the letter to Grimm, which 
first became known in 1931 and which mentioned Diderot s having to re 
move the manuscripts during the night, has given rise to the conclusion that 
this famous incident was a part of the crisis of I759- 39 

During the ensuing weeks Diderot was in such a state that D Holbach 
saw to it that a change of scene was provided. We are in the process of 
making journeys/ wrote Diderot to Grimm on 20 May. The Baron is taking 
me around, and he has no idea of the good he is doing. We have been to 
Versailles, to the Trianon, to Marly. One of these days we are going to 
Meudon. 40 Diderot described the trip to Marly in a beautiful letter to 
Sophie Volland, a letter suffused with a muted and haunting lyricism in 
prose. e je portois tout & travers les objets dcs pas errans et une ame melanco- 
lique! 41 There is no doubt about the wistfulness of his mood. The very 
sound and cadence of the syllables re-enforces the meaning of the words. 

His melancholy was increased by apprehensions about his father s health, 
and this emotion was fortified by a sense of guilt at not being in Langres 
during his father s last days. He s very sick, isn t he? Very old, very worn 
out? ... My father will die, without having me by his side. . . . Ah! my 
friend, what am I doing here? He wants me, he is touching upon his last 
moments, he calls me, and I do not go. ... I beseech you: do not detest 
me. 42 And in a letter to Dr. Theodore Tronchin, thanking him for his 
advice regarding the ailing parent, Diderot wrote, 1 would subtract from 
my own life to protract that of my father, and no one in the world has 


greater confidence in your knowledge than I. I have only one regret, and 
that is my being unable to go and settle down beside the old man, look 
after his health myself, and carry out everything you have prescribed for his 

conservation And then, apologizing for his delay in acknowledging 

Tronchin s prescription, he added: 1 hope that you will find somewhat 
extenuating the lengthy broils into which I have been plunged, and the sort 
of stupid numbness that has followed upon them. Just imagine, Monsieur, 
that several times I have been on the point o exiling myself, that this was 
the advice of my friends, and that I had to muster all the courage of inno 
cence to stand fast against these alarms and remain in the midst of the 
dangers round about me. Now tranquillity commences to be born again. I 
am about to regain obscurity and recover peace. Happy the man whom men 
have forgotten and who can escape from this world without being noticed. 
You think that happiness lies beyond the tomb and I think that it lies in it. 
That is all the difference that there is between our two systems. 43 

Diderot s nervous exhaustion increased the tension of his relationships 
with others. D Holbach displeased him. Grimm was the only friend that he 
had or wanted to have. Sophie Volland s mother was so inscrutable that the 
sphinxes he had seen at Marly reminded him of her. Tour mother s soul is 
sealed with the seven seals of the Apocalypse/ he wrote her daughter. On 
her forehead is written: Mystery. In spite of his misery he forgot himself 
long enough to relish this phrase, which he repeated in a letter to Grimm. 
But there was not just the mother to contend with: Sophie s sister was sus 
picious of him, too. And even Sophie, the incomparable Sophie, had shown 
herself to be jealous. That annoys me. ... I don t like to be under sus 
picion/ And as for jealousy, Mme Diderot had her share of it, and precipi 
tated a quarrel over Sophie Volland so appalling that Diderot went to com 
plain of her to the monk who was her confessor. Diderot did not find people 
easy to live with in I759- 44 

Accompanying his depression was poor physical health. Let s speak no 
more about milk/ he wrote to Grimm. Health will come back to me as 
soon as trouble leaves me. No more troubles, no milk will be needed/ 
Slowly he began to mend, from time to time he felt energy once more stirring 
within him, occasionally his mood of listlessness and lassitude lightened. 
Now and then I feel once more some spark of enthusiasm/ he wrote to 
Grimm on 20 May, and on 5 June he wrote, coining a word that seems as 
quaint in French as it does in English, 1 encyclopedize like a galley slave/ 
But the news of the death of his father, which occurred on 3 June, struck 


him hard. The final blow left for me to receive has fallen: my father is 
dead. 45 

It has been shown by Freud that the death of the father is an exceptional 
moment in the life of any man. With Diderot it seems to have been es 
pecially so, and a Freudian would find complete substantiation of this gen 
eralization in Diderot s saying, as he did in a later letter to Grimm, Other 
sorrows do not prepare a man for this one. 46 For the first time, Diderot 
began to speak of death as something that might happen to him. 47 And 
perhaps because he felt closer to death, he was, in a mysterious way that was 
of enormous importance in the evolution of his creativeness, closer to life. 
From the miseries of this year and from the grimness and drudgery of the 
bleak years that followed it, something was distilled, exquisite and precious, 
in the development of an artist. 48 In the bitterness of misfortunes, heaped 
upon him as upon some hero in Sophocles, there was forged the soul of the 
man who has been called by a great French scholar the mind and the heart 
of the eighteenth century/ 49 

But of all this Diderot could not be aware, nor that, after six more years of 
clandestine editing and toilsome writing, it would be vouchsafed to his 
Encyclopedic to be published in one release with almost no opposition. This 
he could not know. Instead he could only cry out, as he did to Grimm, How 
I have suffered for the past two years! 5 50 I am so tired out that I would like 
to be heard without having to speak, have my letters get done without my 
having to write them, and arrive where I want to be without my having to 
move/ 51 Yet in spite of such lassitude, he turned again to his work for the 
Encyclopedic, with a stubbornness and a tenacity that is close to heroism. 
The circumstances, wrote Lord Morley, under which these five-and-thirty 
volumes were given to the world mark Diderot for one of the true heroes of 
literature/ 52 Diderot was, in many respects, the sanguineous, vehement, 
volatile mortal that Carlyle called him, but he was not volatile in this. We 
swore to see the thing through/ he had written to Grimm, and so, in black 
ness of mood and exhaustion of spirit, he turned once again to his great 
editorial task, to that Encyclopedic of which it has recently and well been 
said, in bicentennial appreciation of its worth, In its subject matter almost 
everything is superannuated, in its aspiration everything is still alive/ 53 

Years later, when all the remaining ten volumes of letterpress were ready 
to appear, he reiterated in his foreword his oft-repeated appeal to posterity. 
We shall have obtained the recompense we expected from our contempo 
raries and from posterity, if we cause them to say, some day, that we have 


nTt lived altogether in vain. No doubt this thought inspired him in 1759, 
too as he turned, with unquenchable determination, to the drudgery of the 
seemingly endless work that lay before him. We swore to see the thing 
through. Perhaps he might even yet see dawn. 


The Nature of the Ultimate Triumph 

distressing events of 1759 brought Diderot close 
JL to the end of his endurance. Ordinarily he was a 
man resilient enough not to be a prey to depression and discouragement for 
long. Nevertheless, that year s dispiriting and discouraging occurrences 
might well have unmanned him had he been unable to draw upon reserves 
which had been silently accumulating through the years. So much seemed 
against him as he drank deeply from the well of loneliness: the contumely 
showered upon the dishonored Encyclopedic by the most august authorities 
of the whole kingdom; the clear imputation that he himself was guilty of 
twenty years of treason; the defection of colleagues and collaborators; the 
alarms regarding his personal safety; his lassitude and lack of resolution, 
aggravated by the sadness and foreboding which he felt because of his 
father s death, all this might permanently have unnerved him had there 
not been going on for a long time a testing which prepared him for a crisis 
so momentous, 

It might all have ended with a whimper. Instead, what seemed like a year 
of ending turned out to be a year of beginning. And the crisis, which might 
have ended in demoralization and despair, culminated in affirmation and 

Eventually the complete Encyclopedic was written and published after all. 
Confronting its suppression in 1759, Diderot s spirit rose to challenge the 
finality of the act. We swore to see the thing through/ And in 1765-6 the 
work was published in all the plenitude of its remaining ten volumes of 
letterpress a phoenix rising from the ashes. To complete the Encyclopedic, 
in view of the discouraging circumstances, required boldness, stamina, 
perseverance and self-confidence. And even to make the try, Diderot had to 
know inside himself that through the apprentice years he had been develop- 




ing and tempering tie qualities and characteristics requisite to cope with an 
emergency like this. 

In the crisis o 1759, Diderot s past entitled him to believe that he had 
developed moral and intellectual qualities equal to doing the job. What 
would an inventory of these qualities include? The answer is spread on the 
record of the preceding chapters. He had abundantly tested the quality of 
his intellectual competence. He knew that he had disciplined himself to 
endure the drudgery of backbreaking work. And his devotion since 1746 
to the idea of the Encydofidie, his perseverance through the years, was 
another test that he had passed: he knew himself to be a man who would 
not quit. The years had proved his doggedness, as they were now to do again. 
His writings, of course, were the visible signs of his qualifications for seeing 
an encyclopedia through and even writing much of it, for his books had 
given solid evidence of encyclopedic range. He had proved his competence 
in areas as diverse as epistemology, psychology, aesthetics, literature, science, 
and technology. But most of all, he knew himself to be the master and 
exemplar of something that was in part an attitude toward the world and in 
part a method of thought. He was a philosophe, indeed THE philosophe, a 
standard-bearer to whom men might repair. He was a tested leader of the 
Enlightenment, the experienced champion of an intellectual approach toward 
science and knowledge that in effect was a political movement. The ten 
years that had passed since the days when he was writing the Letter on the 
Blind or mulling over the prospectus of the Ency dope die or discussing with 
D Alembert its Preliminary Discourse had clarified the issues and confirmed 
in Diderot if it is fair to judge by the books he wrote the consistency 
and sturdiness of those attitudes of intellectual sincerity and integrity and 
open-minded search for truth that had characterized him from early years. 
All these elements of leadership had been measured in him; and now, con 
sciously or unconsciously, he was evidently able to feel that in the present 
crisis he had the qualifications to carry out the task. 

And indeed he had. The qualities requisite for doing so were the qualities, 
enlarged and intensified by the emergency, that we have seen developing 
in the Diderot of earlier days. The emergency brought forth the familiar 
Diderot written large. To paraphrase Talleyrand, the more Diderot 
changed, the more he was the same. The crisis of 1759, in short, produced 
a Diderot who was truly the climax and end-product of his testing years. 

So much for the public Diderot the Diderot identified with the Encydo- 
pedie. But there was another Diderot, one more hidden and withdrawn, 
whose response to the crisis of 1759 was more subtle and more difficult to 


define. In one sense, as we have seen, the crisis of 1759 served to intensify 
the qualities that had been ripening in him during the years of triaL He was 
still the old Diderot, only more so. But in a subtler and perhaps more sig 
nificant sense, he eventually emerged from the crisis a different Diderot. 
Fortunately this elusive change in his personality can be closely followed, 
for it is just at this breaking point in his life that we begin to have the 
riches of his letters to Sophie Volland. Consequently, students of Diderot are 
now realizing that the supreme significance of the crises of 1759 lies in their 
having induced in him a process of maturation built solidly on the founda 
tion of his past experience but utilizing and interpreting it in a different 
way. It is the difference between the young Diderot and not so very 
young, at that, for he was forty-six when the crisis came upon him and the 
mature Diderot. This process of maturation was essential for the production 
of those later works which have become the subjects of such close study and 
such wide admiration in the twentieth century. 

Yet Diderot grew old and died without allowing more than the merest 
handful of people to inspect the abundant evidence of this maturation. 
Masterpieces flowed from his pen and then were put away in a drawer. 
Whether from prudence, whether from soul-weariness at the perverseness 
of his own generation, Diderot laid all his bets on posterity. After 1759 ^ e 
published almost nothing, save of course the Encyclopedic, which is scarcely 
to be compared with unpublished masterpieces like The Nun f Rameau s 
Nephew, D Alembert s Dream, James the Fatalist, or The Refutation of the 
Wor\ by Helvetius Entitled Man! This very reticence denoted a Diderot 
greatly changed, for before 1759 there had been almost nothing that he wrote 
that he did not publish. Now he was content to publish almost nothing at all, 
with the result that posterity has the privilege of knowing his mind and, 
by doing so, of gazing into the central vortex of eighteenth-century thought 
much more intimately than his contemporaries were able to do. Indeed, 
to most of his contemporaries Diderot seemed in his later life to be a most 
unliterary literary man, satisfied to grow fat upon the largesse of Catherine 
the Great and exhibiting, as for example in the circumstances of his hard- 
headed negotiations regarding the marriage of his daughter, little but the 
solid and unexciting qualities of the typical bourgeois. 

But the real Diderot, the Diderot that the present generation (more than 
any of its predecessors) has come to esteem and admire, revealed himself in 
just these unpublished masterpieces. They have in them, characteristic of 
Diderot s later period, a quality both of seeking and having found and still 
of seeking again. They have in them a subtle and powerful dialectic that 


comes from questioning life and answering life. In short, Diderot s later 
writings have an elusive but unmistakable quality of seeming to see far and 
deep into the mysteries of life, further and deeper than he had seen before, 
perhaps further and deeper than any other man of his century save Goethe. 
To use a term liked by Emerson and Carlyle, he became one who really sees, 
a seer. Forsaken by his friends, bereaved of his father, forced to work on the 
Encyclopedic behind locked doors and almost singlehandedly, he found 
resources within himself that might otherwise have lain dormant. The ulti 
mate effect was to refine his thought, make his relations with others more 
subtle, and deepen his humanity. 

List of Abbreviations 

A1EF Cahiers de V Association Internationale Acs ttudes jran$aises. 

AJJR Annales dc la Societe Jean-Jacques Rousseau. 

Annee JJtteraire Annee Littcraire, ed. Elic-Cathcrine Frcron, 202 vols. (Paris, 1754-90). 

D Argenson Rene-Louis de Paulmy, Marquis d Argenson, Journal et memoires, 9 vols. (Paris, 

Asse Eugene Asse, Diderot et Voltaire, d apres les papicrs inedits de la censure, 

Cabinet Historique, nouvelle serie, I (1882), 3-38. 

A.-T. Denis Diderot, Oeuvres completes, ed. Jule* Assczat and Maurice Tourneux, 20 

vols. (Paris, 1875-7). 

AUP Conferences faites a la Sorbonnc a 1 occasion du 2 e centenaire dc ^Encyclopedic, 

Annales de I Vniversite de Paris, XXII ([Oct.] 1952), numero special. 

Barbier, Journal Edmond -Jean-Franc, ois Barbier, Journal historique et anecdotique du regne de 
Louis XV, 4 vols. (Paris, 1847-56). 

B.N., MSS, Fr. Bibliothequc Nationalc, Departement des Manuscrits, Fonds Francais, 

B.N., MSS, Nouv, acq. r. Fonds Nouvcllcs Acquisitions Francaises. 

B.N., MSS, Joly de Fleury Fonds Joly de Fleury. 

Bonnefon Paul Bonnefon, Diderot prisonnier a Vincennes, RHLF, vi (1899), 200-224, 

BSHAL Bulletin de la Societe Historique et Archeologique de Langres. 

CJ Deni* Diderot, Correspondance inedite, ed. Andre Babclon, 2 vols. (Paris, 1931). 

Corr. litt. Friedrich Melchior Grimm, Correspondance litterairc, philosophique et critique 
far Grimm, Diderot, Rayna},etc., cd. Maurice Tourneux, 16 vols. (Paris, 1877-82). 

Courtois, Chronologic* Louis-J. Courtois, Chronologic critique de la vie et des oeuvres de 
Jean-Jacques Rousseau, AJJR, xv (1923), 1-366. 

Cru R. Loyalty Cru, Diderot as a Disciple of English Thought (New York, 1913). 

DNB Dictionary of National Biography. 

Diderot, Corr. Denis Diderot, Correspondance, ed. Georges Roth, i (/7 J- 757) (Paris, 
[1955]); ii (Decembre ijsj-Novembre 1759) (Paris, [1956])- 

Diderot Studies Diderot Studies, ed. Otis E. Fellows and Norman L. Torrey, i (Syracuse, 
1949); n (Syracuse [1952])- 

Encyc. Denis Diderot, cd., Encyclopedic, ou dictionnaire rdsonne des sciences, des arts 

et des metiers, par une societe de gens de lettres, 17 vols. (Paris, 1751-65). 

Encyc., Planches Denis Diderot, ed., Recueil de planches sur les sciences, les arts > liberaux et 
les arts mechaniques, avec leur explication, n vols. (Pans, 1762-72). 




Le Gras 


Henri Guillemin, Les Affaires de 1 Ermitage (i75^757)/ A H R > XXIX 

Charly Guyot, Diderot par lui~memc (Paris, [i953])- 

Journal of the History of Ideas. 

Joseph Le Gras, Diderot et I Encyclopedie (Amiens, 1928). 

Luneau de Boisjermain MSmoire pour Pierre-Joseph-Franfois Luneau de Boisjermain, 
souscripteur de I Encyclopedie . . . (Pans, 177*)- 

May Louis-Philippe May, L Histoire et les sources de 1 Encyclopedic, d apres le registre 

de deliberations et de comptes des e"diteurs, et un memoire inedit, Revue de 
Synthese, xv (1938), 5~ 110 - 

MLN Modern Language Notes. 

MLQ Modern Language Quarterly. 

MLR Modern Language Review. 

Naigeon Jacques-Andre" Naigeon, Memoires historiques et philosophiques sur la vie et les 
outrages de D. Diderot (Paris, 1821). 

PMLA PMLA (Publications of the Modern Language Association of America). 

RDM Revue des Deux Mondes. 

RHLF Revue d Histoire JJtteraire de la France. 

RHPHGC Revue d Histoire de la Philosophic et d Histoire Generate de la Civilisation. 

RLC Revue de Utterature Comparee. 

RQH Louis-Francois Marcel, 4 Une Lettrc du pere de Diderot k son fils, detenu h 

Vincennes (3 septembre I749) ^evue des Questions Historiques, cix (1928), 

JRR Romanic Review. 

Rousseau, cd. Hachette Jean-Jacques Rousseau, Oeuvres completes, ed. Hachette, 13 vols. 
(Paris. 1885-1905), 

Rousseau, Corf. gen. 

Jean-Jacques Rousseau, Correspondance generale f ed. Theophile Dufour 
and P.-P. Plan, 20 vols. (Paris, 1924-34). 

SV Denis Diderot, Lettres a Sophie Volland, ed. Andr Babelon, 3 vols. (Paris, 1930). 

Mme de Vandeul Marie-Angclique de Vandeul, nee Diderot, Memoires pour servir a 1 histoire 
dc la vie ct des ouvrages de Diderot, A.-T., i, pp. xxix-lxii. 

Vcnturi, Jeunesse Franco Venturi, Jeunesse de Diderot (de 1713 a 1753) (Paris, 1939). 
Venturi, Origin* Franco Venturi, Le Origini dett Enddopedia (Florence, 1946). 

Voltaire, ed. Moland Voltaire, Oeuvres completes, cd. Moland, 52 vols. (Paris: Garnier freres, 




1. Diderot, Corr., n, 194. 

2. Encyc. t ix, 244-5. 

3. Diderot, Corr., n, 207-8. For an attempt by Diderot to represent this speech phonetically, 

see Diderot, Corr., i, 143. 

4. Louis-Francois Marcel, Le Bapteme dc Diderot, Semaine religieuse du diocese de Langres, 

1 8 Oct. 1913, 675-80; George R. Havens, The Dates o Diderot s Birth and Death, A/LW, 

LV (1940), 3i-5- 

5. Louis -Francois Marcel, Le Frere de Diderot (Paris, 1913), 3 and n. 

6. Ibid. 22-3; Louis-Francois Marcel, Un Oncle de Diderot: Antoine-T homos Diderot de I Ordre 

des Freres Precheurs (1682-1756} (Liguge [Vienne], I93)> 3- 

7. Marcel, Le Frere de Diderot, 14-23, 191-7- 

8. 4 Sept. 1741 (Louis-Frangois Marcel, Le Manage de Diderot [Largcntiere (Ardeche), 1928], 

17 n.; Marcel, Un Oncle de Diderot, 10 n.). 

9. RQH, non.; Martin Lopelmann, Der junge Diderot (Berlin, 1934), 9~ 10 - 

10. Lopelmann, Der junge Diderot, 10. 

11. Diderot, Corr., n, 119, 157. 

12. SV, i, 198 (30 Sept. 1760). 

13. A.-T., xvn, 333, 334, 335- 

14. Francois Helmc, Diderot dans notre art. A propos de son bi-centenaire, Presse Uedicale, 

vol. n for 1913, 1247. 

15. A.-T., xvn, 335. r 

16. SV, n, 266 (i Aug. 1765). 

17. Memorandum ca. 1821 by Mme de Vandeul for her doctor (Jean Massiet du Biest, La Fills 

de Diderot [Tours, 1949], 218). 

1 8. Massiet du Biest, 186; Louis-Francois Marcel, La Soeur de Diderot: Denise Diderot (27 

Janvier 1715-26 mars 1797) (Langres, 1925), 42 n. 

19. Massiet du Biest, 175; A.-T., xvn, 335. 

20. Facts in this paragraph are from a registry book in the Archives municipales at the Hotel 

de Ville at Langres: Etat civil, 1699 & 1721, de la Paroisse de Saint-Martin/ Diderot s aunt, 
Catherine Diderot (d. 26 Dec. 1735 at the age of 46), is sometimes confused with his 
younger sister, the second Catherine (Diderot, Corr., i, 23). 

21. BHLF, LV (1955). 2 3<5. 

22. Mme de Vandeul, Iviii; Massiet du Biest, 207. 

23. Marcel, Le Frere de Diderot, i. 

24. Mme de Vandeul, Iviii-lx. The Houdon bronze is in the council room of the Hotel de Ville 

at Langres. 

25. Mme de Vandeul, xxix. 

26. A.-T., xi, 250. 

27. A.-T., xi, 253. 

28. A.-T., xrv, 439. 

29. Herbert Dieckmann, Invcritaire du Fonds Vandeul et Inedits de Diderot (Geneva, 19 51), 204. 

30. Lopelmann, Der junge Diderot, 21-2; Louis-Francois Marcel, Diderot ccolier, EHLF, 

31. Regarding the Jesuits and secondary education in France, see Pierre Clarac, ^ Encyclopedic 

et les problemes d education, AUP, xxn ([Oct.] 1952), numero special, 215; also the excel 
lent article by Marcel Bouchard, L Enseignement des Jesuites sous 1* Ancien Regime, Informa 
tion Historique, xvi (1954), I2 7~34- , . 

32. Diderot was born at 9> Place Diderot (then called Place Chambeau). On 20 July 1714, his 

father bought the house across the square at 6, Place Diderot, occupied by the Diderot 
family for the rest of the eighteenth century. The marker upon it which claims that it is 



Diderot s birthplace is incorrect: see Leon Guyot, La Maison natale de Diderot, BSHAL, 
1931, 34-40; Hubert Gautier, U Pte dc D.dtrot, i68 S - I7 59- (Mouhas, 

1933) 8. 

33 A -T., xvn, 359; Marcel, Diderot toiler, RHLF, xxxiv, 382-3- 

34. Maurice Tourneux, Diderot ct Catherine II (Paris, 1899)* 349-50, 353- 

35. A.-T., n, 333- 

37*. tS 3 45 ff Oct. 1760). Mme de Vandeul, xxix-xxx, and Naigeon, 3, describe a similar 

incident, but with much more sensational details. ^ ^ . 

38 A -T m 421, 468-88. Diderot s familiarity with the classics is emphasized by Erie M. Steel, 
* Diderot s Imagery: A Study of a Literary Personality (New York, 1941), 48-51- 

39. A.-T-, m, 478. 

40. A.-T., ni, 481. 

41. Corr. litt., vm, 151-3. . ._., , , . 

42. A.-T., vi, 289-302; Corr. lift., vm, 153-4- Cf. Ernst Robert Curtius, Diderot und Horaz, in 
his Europaische Uteratur und lateinisches Uittelalter (Berne, 1948), 556-64. 

43. A.-T., xvm, 167. 

45! Gu^avrChar"lL*and Le"on Herrmann, Diderot, annotateur de Perse/ RHLF, xxxv (1928), 

46. A.-T,, xrv, 438. 

47. A.-T., vi, 298. 


1. Mme de Vandeul, xxx. 

2. Marcel, Le Frere de Diderot, 25. 

3. Ibid. 30-33. The Canon died on 28 April 1728. In the Entretien d un pere avec ses enfants, 

Diderot gives a rather different account of the succession to the prebend and the Canon s 
death (A.-T., v, 302). The circumstances as reconstructed by Canon Marcel seem to me to 
have more verisimilitude. 

4. Mme de Vandcul, Ix. . 

5. A.-T., vi, 182. Diderot may have been very gravely ill about 1729, for he is alleged to have 

declared in 1747 that at the age of sixteen, finding himself in danger of death, he had called 
a priest and received the sacraments (Bonnefon, 203), 

6. A.-T., x, 391. See also Diderot s remark in a memorandum for Catherine II (Tourneux, 

Diderot et Catherine II, 159). 

7. Mme de Vandeul, xxx. 

8. A.-T., xvii, 231, s.v. Subvcnir.* 

9. Antoine Taillefer, Tableau historique de I esprit et du caractere des litterateurs jran$oi$, 

deptiis la renaissance des lettres jusqu en 1785, 4 vols. (Paris, 1785), rv, 215 flf. 

10. Jean Massiet du Biest, Lettres inedites de Naigeon a M r et M me de Vandeul (1786-1787), 
conccrnant un pro jet d edidon des oeuvres de Diderot et opinion de ceux-ci sur le meme 
sujet, d apres leur correspondance inedite (1784-1812), BSHAL, I Jan. 1948, 2. Nothing is 
otherwise known as to the identity of this Mme Frejacques. 

11. A convincing argument for the year 1728 is made by Marcel, Diderot ecolier, RHLF, xxxrv, 
390-91; cf. Lopelmann, Der junge Diderot, 36 n. 

12. The unidentified girl: Diderot, Corr., n, 195. Diderot s early feelings for Mile La Salctte: 

Diderot, Corr., i, 145. She married Nicolas Caroillon on 16 April 1736 (Louis-Francois 
Marcel, Les Premiers Aerostats a Langres, BSHAL, vm [1919], 8). 

13. SV, i, 187 (25 Sept. 1760). 

14. Canon [Louis-Francois] Marcel, La Jeunesse de Diderot, 1732-1743, Uercure de France, 

ccxvi (1929), 68 n. 

15. Mme de Vandeul, xxx-xxxi, 
1 6. A.-T., x, 351. 

17. Johann Georg Wille, Uemoires et journal, ed. Georges Duplessis, 2 vols. (Paris, 1857), I, 
91. "Wille dates this meeting in 1740, but Emilia Francis (Strong), Lady Dilke, French En- 

NOTES FOR PAGES 25-30 35! 

gravers and Draughtsmen of the XVlll Century (London, 1902), 73, proves that it must 
have been after May 1742. 

1 8. Taillefer, Tableau historique, rv, 217. 

19. Mmc de Vandeul, xxx; Naigeon, 5. 

20. Mme de Vandeul, xxxi. Bernis, however, makes no mention of Diderot (Francois -Joachim 

de Pierre, Cardinal de Bernis, Memoires et lettres, ed. Frederic Masson, 2 vols. [Paris, 1903], 
I, 16-20). 

21. Marcel, Diderot ecolier, KH.LF, xxxiv, 396-9; R. Salesscs, TDiderot et I Univcrsite, ou le$ 

consequences d une mystification, Revue Universitaire, April 1935, 322-33; cf. Ralph Bowen, 
The Education of an Encyclopedist, Teachers of History: Essays in Honor of Laurence 
Bradford Packard (Ithaca [N.Y.], 1954), 33-9. My friend, Professor Francois Denoeu, 
suggests the possibility that Diderot was a pensionnaire at one college and went out to special 
lectures at the others. 

22. Salesses, in Revue Universitaire, April 1935, 329. Cf. Aram Vartanian, Diderot and Descartes 

(Princeton, 1953), 40-43. 

23. This ingenious supposition is set forth by Jean Pommier, Diderot avant Vincennes (Paris, 

I939)> 9- Yvon Belaval, L Esthetique sans paradoxe de Diderot (Paris, 1950), 15, thinks 
that Diderot transferred from the College d Harcourt to Louis-le-Grand. An anonymous 
polemical pamphlet of 1759 declared that Diderot did his philosophy* under a Dominican. 
If this was true, it is clear that even if Diderot was in the Jesuit Louis-le-Grand for his 
first year of studies in Paris, he did not remain there for his second (Lettres sur le VII 6 
volume de I Encyclopedie [n.p., 1759], 37 n.: M. Diderot a fait son cours de Philosophic 
sous le P. Rozet, dorninicain ). Evidence of Diderot s master of arts degree is on fol. 35 of 
a University register ( Index Magistrorum in Artibus, B.N., MSS, Fonds latin 9158); re 
produced in Guyot, 6. 

24. A.-T., i, 383-4; but as M. Salesses, Revue Universitaire, April 1935, 325, points out, the 

Lettre sur les sourds et muets was published anonymously, and therefore Diderot s references 
to Louis-le-Grand and to Father Poree may have been intended merely to mystify. 

25. Naigeon, 8; Salesses, Diderot et 1 Universite, Revue Universitaire, April 1935, 3250. 

26. Diderot, Corr., i, 23, 29. 

27. Mme de Vandeul, xxxi-xxxii; she implies that Diderot read law with the procureur before 

he tried tutoring, but Naigeon, 15, says that it was the other way around. Regarding Clement, 
see Marcel, La Jeunesse de Diderot, Mercure de France, ccxvi, 49~53- 

28. Mme de Vandeul, xxxiii-xxxiv. There were several persons of the name of Randon con 

temporary with Diderot. Assezat declared (A.-T., i, xxxiv n.) that it was Randon de Boisset, 
and that he was the Randon to whom Diderot referred in his Salon of 1767 (A.-T., xi, 274). 
But he died a bachelor (Comtc L. Clement de Ris, Paul Randon de Boisset, 1708-1776, 
Bulletin du Bibliophile et du Bibliothecaire, 39* annee [1872], 201). Canon Marcel, *La 
Jeunesse de Diderot, Mercure de France, ccxvi, 60-64, believes that Diderot s employer was 
an Elie Randon de Massanes d Haneucourt; Naigeon, 13-15, stated that it was a M. Randon 
d Hannecourt. 

29. This characteristic of Diderot is commented upon by Steel, Diderot s Imagery, 175-7- 

30. Mme de Vandeul, xxxiii. 

31. A.-T., m, 460. This work was by Antoine Deparcieux (1703-68), Nouveaux Traites de 

trigonometric rectiligne et spherique . . . avec un traite de gnomonique (Paris, 1741). 
It contains no mention of the part played by Diderot in its preparation. 

32. Histoire de Grece, traduite de I Anglois de Temple Stanyan, 3 vols. (Paris: Briasson, 1743), 

33. Mme de Vandeul, xxxii-xxxiii. Her name was Helene Brulc (Marcel, La Soeur de Diderot, 

34. Mme de Vandeul, xxxvii; the same story, almost verbatim, in Taillefer, Tableau historique t 

iv, 224-5. Frangois Genin in Nouvelle Biographic generate (Hoefer), s.v. Diderot, 82, 
dates this 1741, but adduces no proof. 

35. Diderot, Corr., i, 23; my italics. A.-T., xm, 210, s.v. Acier. 

36. Mme de Vandeul, xxxiv-xxxvi. . . 

37. A.-T., ix, 1 68. The work alluded to is Isaac Newton, Philosophiae naturalis pnnctpta 

mathematica, cd. Thomas Le Seur and Francois Jacquier, 4 vols. (Geneva, 1739-42). 

2- 2 NOTES FOR PAGES 31-8 

38. A.-T-, vin, 398; cf. A.-T., vn, 108. 

39. A.-T., vii, 400-401. 

li" For a description ca. 1726 of the discussions that went on at the Ca& Procope, see Charles 
Pineau Duclos, Oeuvres completes, 10 vols. (Paris, 1806), x, 55-69. CL J acc * ues Hlllairet > 
Evocation du vicux Paris, 2 vols. (Paris, [1952-3])* ^ 619-20. 

42. Jean-Nicolas Dufort de Cheverny, Memoires, 2nd ed., 2 vols. (Paris, 1909), I, 459- 

43. A.-T., v, 411-12. .... , 

44. A.-T., x, 349. The book in question was Venus dans le cloitre, ou la Rehgieuse en chemise, 

first published at Cologne in 1683. 

45. A.-T., vn, 404. 

46. SV, n, 101-2 (28 July 1762). . 

47. R. Salesses, Les Mysteres de la jeunesse de Diderot, ou 1 aventure theologique, Uercure 

dc France, CCLXX& (193?) 5* n. . 

48. Archives Departementales de la Haute-Marne, Fonds Vandeul -4, quoted by Gautier, 

Le Pere de Diderot, 17. Cf. the same document: Vous, mon fils 1 aine . . . vous savez 
ce que j ai fait pour vous; j ai depense" tant pour vous que pour votre soeur la religieuse et 
pour Diderot le pretre plus que le patrimoine que, moi et Angelique, nous avons eu, tant 
en mariage que de succession (ibid.). 

49. Marcel, Diderot ecolier, RHLF, xxxrv, 400. 

50. A.-T., xi, 265-6. 

51. Encyc., vn, 262^ s.v. Tour-rare. 1 See also ibid, ix, 8930, s.v. Maitre es arts. 

52. Encyc., v, 5 a. 

53. Salesses, loc. cit., Mercure de France, CCLXXX, 503-11. M. Salesses thinks it probable that 

Diderot even knew Hebrew (ibid. 511-12); but cf. Joseph Edmund Barker, Diderot s 
Treatment of the Christian Religion in The Encyclopedic (New York, 1941), 24-6. 

54. Diderot, Corr., I, 25-6. In 1784 the grandson of Pierre La Salette, he being also the son- 

in-law o Diderot, wrote that La Salette had undertaken to try to get the elder Diderot 
to settle an annuity of 200 livres upon his older son but that his good offices were un 
successful (Massiet du Biest, Lettres inedites . . . , [supra, ch. 2, note 10], 2-3). 

55. Diderot, Corr., i, 26. 

56. L Abbe Prevost, Manon Lescaut (Oxford: BlackwelPs French Texts, 1943)* *> 93"4; &** 

edition is a facsimile of the authoritative 1753 edition. 

57. A.-T., ii 399- 


r. Mme de Vandeul, xxxvii. Lester Gilbert Crocker, La Jeunesse de Diderot: Quelques preci 
sions,* by L. G. Krakeur, PMLA, LVII (1942), 134-5, believes the couple became acquainted 
in 1742. For lively (though undocumented) articles regarding Mme Diderot, see Henriette 
Celarie, Le Philosophe mal marie: Diderot et son epouse, Monde Franfais, xn (1948), 
39-60, and Jules Bertaut, Madame Diderot/ Revue de France, i June 1924, 574-94, re 
printed in his Egeries du XVIII 6 siecle (Paris, [1928]), 183-212. 

2. For Anne-Toinette s baptismal certificate, see Marcel, Le Mariage de Diderot, 8. 

3. The principal building of this convent is now the Musee de 1* Assistance Publique. Regarding 

Mme Diderot s family and ancestry, see Massiet du Biest, La Fille de Diderot, 7 n.; also 
Diderot, Corr., i, 24. Her elder sister, Marie-Antoinette Champion, married Michel Billard 
(or Billaud). In her declining years she lived with the Diderots (Marcel, Le Mariage de 
Diderot, 9-10; Louis Marcel, Un Petit Probleme d histoire religieuse et d histoire litteraire: 
La Mort de Diderot, 1 Revue d Histoire de I Eglise de France, xi [1925], 40 n., 46 n., 211 n.). 
In the marriage contract of Diderot s daughter, as printed in Cahiers Haut-Marnais, No. 24 
(i er trimestre 1951), 19, she is referred to as the widow of Michel Belliard. 

4. Mme de Vandeul, xxxvii-xxxviii. 

5. Ibid, xxxviii; also Massiet du Biest, La Fille de Diderot, 207. 

6. SV, n, 324 (21 Nov. 1765). 

7. See Pierre Mesnard, Le Caractere de Diderot, Revue de la Mediterranee, vn (1949), 279; 
see also his Le Cos Diderot: Etude de caracterologie litteraire (Paris, 1952), 67. 

NOTES FOR PAGES 38-46 353 

8. Comte Pierre-Louis Roederer, Sur Diderot, Journal de Paris, 17 Fructidor An vi [3 Sept 

1798]; reprinted in Roederer, Opuscules meles de literature et de philosophic (Paris, An 
VIII [1800]), 53; and in Roederer, Oeuvres, 8 vols. (Paris, 1853-9), *v> 2I 5- 

9. Mme de Vandeul, xxxviii-xxxix. 

10. Diderot, Corr., i, 29. 

11. Naigeon, 26. 

12. Crocker, La Jeunesse de Diderot, PMLA, LVII, 134. 

13. Christmas Eve, 1742 (Diderot, Corr., i, 37). 

14. Diderot, Corr., I, 36. 17 Dec. 1742, according to Lester G. Crocker, La Correspondance de 

Diderot, by L. G. Krakeur (New York, 1939), 109. 

15. Diderot, Corr., i, 35-6. Diderot s brother entered the seminary eight days before Diderot 

arrived in Langres in 1742 (ibid. 35); he received the tonsure on 29 June 1743, and entered 
holy orders sometime in 1746, probably in May (Marcel, Le Frere de Diderot, 42-4). 

1 6. Diderot s father mentioned this book in his will (Gautier, Le Pere de Diderot, 15); cf. 

Marcel, La Jeunesse de Diderot, Mercure de France, ccxvi, 78 n. 

17. Mme de Vandeul, Iviii. Cf. Georges May, Diderot et La Religieuse (New Haven, 1954), 


18. 3 Sept. 1749 (RQH, no). 

19. Diderot, Corr., i, 38, 39. 

20. Diderot, Corr., i, 40. 

21. Arch, depart., Haute-Marne, Fonds Vandeul, n E 3; published in Diderot, Corr., i, 41-2, 

and in Marcel, Le Manage de Diderot, 21-2. This letter reproduced in facsimile in Cahiers 
Haut-Marnais, No. 24 (i er trimestre 1951), Supplement illustre. 

22. Evelyn B. Hall (pseud. S. G. Tallentyre), The Life of Mirabeau (London, 1908), 


23. Diderot, Corr., i, 43-4. This aunt was probably his godmother, Claire Vigneron (b. 17 Nov. 

1665; date of death unknown). So far as is known, no other of Diderot s aunts was alive 
at this time (Marcel, Le Frere de Diderot, 193, 197). 

24. A.-T., i, Ixiii. 

25. Mme de Vandeul, xxxix. 

26. CI, n, 17 n. . 

27. CI, n, 122. The marriage contract was signed 26 Oct. 1743 (Dieckmann, Inventaire, 162). 

28. Auguste Jal, Dictionnaire critique de biographic et d histoire . . . d apres des documents 

authentiques inedits, 2nd ed. (Paris, 1872), 495. 

29. Mme de Vandeul, xxxix. She states, however, that the marriage took place in ^1744, an 

example of how her account of her father is not to be trusted implicitly. For Saint-Pierre- 
aux-Boeufs, see the Abbe Lebeuf, Histoire de la vitte et de tout le diocese de Paris, 5 vols. 
(Paris, 1883)5 i, 317-19; and also the same work, Rectifications et additions, by Fernand 
Bournon (Paris, 1890), 329-30. Cf. the Marquis de Rochegude and Maurice Dumolin, Guide 
pratique a travers le vieux Paris, nouv. ed. (Paris, 1923), 41. 

30. Diderot, Corr., i, 39. 

31. Ibid. 46. 

33". Charles *Nauroy, Revolutionnaires (Paris, 1891), 244; also in his Le Curieux, i (1883-5), 

34. Nauroy, Revolutionnaires, 246; Edmond Beaurepaire, *Les Logis dc Diderot, Revue des 

Fran?ais, xvn (1913), 313- 

35. RQH, 109. 

36. Bonnefon, 203. 

37. Mme de Vandeul, xl. 

38. Courtois, Chronologic, 36; Rousseau, ed. Hachette, vni, 199. 

40! Co urtois 1 , Chronologic/ 41, 48, 40, and esp. 50 n.; Louis Ducros, Jean-Jacques Rousseau: De 
Geneve a I Hermitage (/7- 7J7) (Paris, 1908), 131 n, argues that the summer of 1746 
is the correct date. 

41. Rousseau, ed. Hachette, vin, 246. 

42. CI, xi, 14 n. 




1. A.-T., n, 378. 

2. Bonnefon, 212. 

4 ^Per^oquet, ou melange dc diverse* pieces interessantes pour V esprit et pour It coeur, a 
vols. (Frankfurt am Main, 1742), i, 78-80; also A.-T, ox, 63-4. See Gustave L. Van^Roos- 
broeck, Diderot s Earliest Publication; MLN, xxxrx (1924), 504~5- The identification of 
Baculard d Arnaud is made by Venturi, Jeunesse, 41-2, 34? 34 2 - 

5. Diderot, Corr., i, 29-30. 

J" Herbert DieSmann, Diderot, membre honoraire de la Societe" d Antiquaires d Ecosse Cahiers 
Haut-Marnais, No. 24 (i* r trimcstre 195*), 25. F r a photograph of Diderot s dralt, see 
ibid. Supplement illustre. 

8. See above, chap. 2, note 32. The pnW%<* were dated, respectively, 14 July, 14 Dec. and 

19 Dec. 1742 (B.N., MSS, Fr. 21958, foil. 30-31, 81-2, 84). 

9 . /0a/ rf Sgavans, August 1743, 45i~62; Sept. I745> 547-555 April 1746, 231-8, this 

quotation, 238. 

10 J>* Nouvelles Litttraires de Berlin, 21 Dec. 1773, Quoted by Tourneux, Diderot et Catherine 
II, 529. The translation comprised one volume of the five-volume (unauthorized) edition 
of Diderot s works published at London [Amsterdam 1 ] in 1773- 

11. Mmc de Vandeul, xl. . 

12. Cf. Venturi, Jeunesse, 46-71, 342-58; Pierre Hermand, Les Uees morales de Diderot (Paris, 

1923), 50-63; Cru, 119-33; Pomrnier, Diderot avant Vincennes, 20-25. 

13 Hippolyte BufTenoir, Les Portraits de Jean-Jacques Rousseau (Paris, 1913), i, 240, plate 48. 

Diderot also gave a copy, with the flattering inscription Totum muneris hoc tui est, to^ a 
Mme de Sainte-Croix, of whom nothing else is known; for this facsimile, see Pierre Beres: 
Catalogue 48: Beaux Uvres anciens (Paris, [i95 I? l)> item II8 - 

14 P. 200. On the Journal dc Trevoux, see Gustave Dumas, Histoire du Journal de Trevottx 
depuis 1701 jusqu en 1762 (Paris, 1936), passim, esp. 137, and Albert Gazes, Un Advcrsairc 

de Diderot et des philosophes: Le P. Berthier, in Melanges offcrts . . . a M. Gustave Lanson 
(Paris, 1922), 235-49, esp. 239-40. 

15. Journal des Sgavans, April 1746, 219. 

16. Lopelmann, Der junge Diderot, 84, 100-101, 121-2, esp. remarks on the skill of Diderot t 

17. Such, too, is the judgment, in a very perspicacious essay, of a former member of the French 
Academy (Charles de Remusat, Shaftesbury, RDM, 15 Nov. 1862, 475)- 

1 8. A.-T., i, 1 6. 

19. A.-T., i, 75. The importance of this passage has been emphasized by Venturi, Jeunesse^ 

355; by Pommier, Diderot avant Vincennes, 25; and by Mesnard, Le Caractere de Diderot,* 
Revue de la Mediterranee, vn, 283, who calls it 1e modele unique de la sensibilite. 

20. A.-T., i, 25 n. 

21. Jugcmens sur Quelques Outrages Nouveaux, vni (Avignon, 1745)? 86-7. 

22. A.-T., i, 10. 

23. Vcnturi, Jeunesse, 50; Hermand, Les Idees morales de Diderot, 56; John Morley, Diderot 

and the Encyclopaedists, 2 vols. (London, 1878), i, 59-61. 

24. Venturi, Jeunesse, 59-61. 

25. A.-T., i, 32-6. 

26. Venturi, Jeunesse, 359-63; Rene P. Legros, Diderot et Shaftesbury, MLR, xix (1924), 

I 92-4- 

27. Marcel, Le Frere de Diderot, 43-4. The brother was a student in canon law at Pans from 

1744 (probably) until early 1747 (ibid. 43, 47). Succeeding editions of the translation of 
Shaftesbury were (i) Philosophic morale reduite a ses prindpes, ou Essai dc M. S.*** 
sur If merite et la vertu (Venice [Paris], 1751); (2) Les Oeuvres de Mylord Comtc de 
Shaftesbury, 3 vols. (Geneva, 1769), n, 3-166, but with no intimation that Diderot was 
the translator. The Shaftesbury Essai was included in all five of the eighteenth-century col 
lected editions of Diderot s works. 


28. Mark Twain, A Majestic Literary Fossil/ Writings (Author s National Edition), rxi, 524- 


29. Bonnefon, 212. Cf. James Doolittle, Robert James, Diderot, and the Encyclopedic/ ULN, 

LXXI (1956), 43I-4- 

30. Registre des privileges accordes aux auteurs et libraires, 1742-1748* (B.N., MSS, Fr. 

21958, fol. 262). The tide page is dated 1746, but the first volume was published 
shortly before October 1745 (Journal des Sgavans, Oct. 1745, 634); the second, promised for 
June 1746, was ready for distribution on n May of that year (Journal de Trevoux, 
July 1746, 1541). An Italian translation (Dizionario universde di medicina . . . tradotto 
dall originale inglese dai Signori Diderot, Eidous e Toussaint . . .) was published at 
Venice in 1753. 

31. DNB, s.v. J 21 * 168 * Robert, M.D. In 1771 Diderot reviewed admiringly (but without 
knowing the identity of the author) the Histoire dc "Richard Savage, just translated into 
French by Le Tourneur (A.-T., ix, 451-2), but aside from these slight instances, no rela 
tionship between Diderot and Johnson is known. 

32. Mme de Vandeul, xl. 

33. Arrest de la cour du Parlement, qui ordonne qu un livrc intitule, Les Moeurs . . . sera lacere 

& brule par I Executeur dc la Hautc-Justice (Paris: P.-G. Simon, 1748), mounted in B.N., 
MSS, Fr. 22176, foil. 258-9. Benedict XIV placed the book on the Index in 1757 (Franz 
Heinrich Reusch, Der Index der verbotenen Eucher, 2 vols. [Bonn, 1883-5], n, 873). 

34. B.N., MSS, Nouv. acq. fr. 10783, fol. 124. See also Maurice Pellisson, Toussaint et le livrc 

des "Moeurs",* Revolution frangaise, xxxrv (1898), 385-402; and Gustavc Charlicr, Un 
Encyclopedists a Bruxelles: Fr.-V. Toussaint, 1 auteur des "Moeurs", Annales Prince de 
Ligne, xvm (1937), 5-22. 

35. Encyc. f I, xlij; Corr. litt. t vi, 391-2. See ibid, vr, 143-4, 285, 454 for notices of other 

translations by Eidous. 

36. Corr. litt., vn, 234. 

37. Ibid. 308. For a similar judgment on Eidous, see 1 Abbe Sabatier de Castres, Les Trots 

Siecles de la litterature jranqaise, 5th ed., 4 vols. (The Hague, 1778), n, 148. 

38. Bibliotheque de 1 Arsenal: Archives de la Bastille 10301 (14 Feb. 1748). In 1749, Eidous 

was reported to be thirty-six (B.N., MSS, Nouv. acq. fr. 10782, fol. 2). 

39. Dieckmann, Inventaire, 3-4. 

40. Baptism: Nauroy, Revolutionnaires, 244-5; cf. Diderot, Corr., i, 53. For the convulnonnaires , 
see Albert Mousset, L ttrange histoire des convulsionnaires de Saint-Uedard (Paris, 1953). 

41. Bonnefon, 210. 

42. Arrest de la cour du Parlement . . . Du 7. Juillet 1746 (Paris: P.-G. Simon, 1746), 2, 

mounted in B.N., MSS, Fr. 22176, foil. 210-11. 

43. Gustave Lanson, Questions diverses sur rhistoire de 1 esprit philosophiquc en France avant 

1750, RHLF, xix (1912), 2-4. 

44. Ira O. Wade, The Clandestine Organization and Diffusion of Philosophic Ideas in France 
from 1700 to 1750 (Princeton, 1938), 10-18, 166, 294, et passim. 

45. Vcnturi, Jeunesse, 73-4. 

46. See the reports of Bonin and Mme de La Marche during 1748 and 1749 (Bibliotheque de 
1 Arsenal: Archives de la Bastille 10300-10302). Regarding the latter, see also Hugues de 
Montbas, La Litterature clandestine au XVIII e siecle, RDM, 15 July 1951, 326-7- For a 
comprehensive account of the administration of censorship, see David T. Pottinger, Censor 
ship in France during the Ancien Regime/ Boston Public Library Quarterly, vi (i954) 
2342, 84101. 

47. For bibliographical information regarding the Pensees philosophiques, see the critical edition, 

ed. Robert Niklaus (Geneva, 1950), 47-63; also further information in Diderot, Lettre sur 
les aveuglcs, cd. Robert Niklaus (Geneva, 1951), ixvi. Regarding the German translation 
(Halle, 1748), see Joachim Abrahams, Diderot, franzosisch und deutsch, Romanische 
Forschungen, LI (1937)* 42-50, 387- 

48. Mme de Vandeul, xlii. Taillefer, Tableau historique, iv, 263-4, says that Diderot wrote 

it in four days. 

49. Shaftesbury s influence was alleged by [Georges-P.-G. Policr de Bottens], Pensees chretiennes 

miset en parallel^ ou en opposition, avec les Pensees philosophiques (Rouen, I747> 7; * 


also by the reviewer of the Pensees philosophiques writing in the Bibliotheque Raisonnee 
des Outrages des Savants de I Europe, XL (Jan.-March 1748), 112-23. 

50. David Finch, La Critique philosophique de Pascal au XVIII* siecle (Philadelphia, 1940), 

39-46; Morley, Diderot and the Encyclopaedists, i, 52. 

51. Albert Monod, De Pascal a Chateaubriand: Les Defenseurs franfais du Christianisme de 

1670 a 1802 (Paris, 1916), 304, 509. 

52. The importance and novelty o Diderot s biological approach is well brought out by Aram 
Vartanian, From Deist to Atheist: Diderot s Philosophical Orientation, 1746-1749, Diderot 
Studies, i, 48-52. Cf. Lester G. Crocker, Pensee xix of Diderot, MLN, LXVII (1952), 433~9> 
and the ensuing controversy between Drs. Crocker, Vartanian, and James Doolitde, MLN, 

3LXVIII (l953)j 282-8. 

53. Robert Niklaus, Les Pensees Philosophiques de Diderot, Bulletin of the John Rylands 
Library, Manchester, xxvi (1941-2), 128; Guyot, 67. 

54. For a bibliography of refutations of the Pensees philosophiques, see the Niklaus editions 

(supra, note 47), 58-63 and Ixvi, resp.; also Robert Niklaus, Baron de Gaufridi s Refuta 
tion of Diderot s Penseef Philosophiques, RR, XLIII (1952), 87-95. The young Turgot 
wrote a criticism of the Pensees philosophiques (Turgot, Oeuvres, ed. Gustave Schelle, 

5 vols. [Paris, 1913-23], i, 87-97). This remained in manuscript, however, and it is 
not certain just when it was written. Mention might also be made of Pierre-Louis-Claude 
Gin, DC la Religion, 4 vols. (Paris, 1778-9)? * *353 nl > P* rt iii, 103, 237-9, 253-4; ni, 
part iv, 54-5, 162-4, 203-4, 215-16, 227-8, 277-8; iv, 238. For summaries of the refutations 
of the Pensees, see Venturi, Jeunesse, 91-104, 363-7, and Monod, De Pascal a Chateaubriand, 

55. David-Renaud Boullier, in Lettre xn (i Feb. 1748), Le Controlleur du Parnasse, iv, 10; 
Polier de Bottens (supra, note 49), 8. 


1. A.-T., i, 269-70. 

2. [Jacques-Andre Naigeon, ed.], Recueil philosophique, ou Melange de pieces sur la religion 

6 la morale, 2 vols. (London [Amsterdam], 1770), r, 105-29; in A.-T., i, 261-73. Naigeon 
attributed this falsely to Vauvenargues (Recueil philosophique, n, 253), because Diderot was 
still alive, while Vauvenargues had died in 1747. This piece was in part inspired by 
Wollaston s The Religion of Nature Delineated (Lester G. Crocker, The Embattled 
Philosopher: A Biography of Denis Diderot [East Lansing (Mich.), 1954], 28). 

3. So, too, thinks M. Pommier (Diderot avant Vincennes, 38n.); but cf. Venturi, Jeunesse, 
72-3, 106-7. 

4. A.-T., i, 270, 264, 272. 

5. Although Naigeon declared in 1786 that Diderot wrote the Promenade du sceptique in 

1749 (Massiet du Biest, Lettres inedites. . . . [supra, ch. 2, note 10], 4), all other 
authorities believe it to have been written in 1747. Wade, Clandestine Organization, 166, 
found a note in the library at Fecamp declaring that the Promenade was composed in 

6. A.-T., i, 186-7. 

7. Bonnefon, 202. 

8. Nauroy, Revolutionnaires, 245. 

9. Bonnefon, 203. Berryer was appointed Lieutenant-General of Police on 27 May 1747 

(B.N., MSS, Fr. 22176, fol. 238). 
10. A.-T., i, 192. 
n. A.-T., i, 215, 220. 

12. A.-T., vi, 30. 

13. See supra, ch. 4, note 21; Pommier, Diderot avant Vincennes, 412. Cf. A.-T., i, 15, 185. 

14. A.-T., rv, 443-8. Cf. A.-T., n, 524-6. Leif Nedergaard, Notes sur certains ouvrages de 
Diderot/ Orbis Litterarum, vni (1950), 5. 

15. Steel, Diderot s Imagery, 262-3; but cf. Venturi, Jeunesse, 108-10. 

1 6. A.-T., i, 199. 


17. A.-T., I, 212. 

18. Vartanian, From Deist to Atheist, 1 Diderot Studies, i, 52-5, 60-61. Sec also the analysis 

o the Promenade in Venturi, Jeunesse, 108-19; and Paul Vernicre, Spinoza et la pensee 
jrangaise avant la Revolution (Paris, 1954), 567-72; also Paul Verniere, cd., Oeuvres 
philosophiques, by Diderot (Paris, [1956]), x. 

19. J. Delort, Histoire de la detention des philosophes et des gens de lettres a la Bastille t a 

Vincennes, 3 vols. (Paris, 1829), n, 213 n. Concerning D Hemery, consult Ernest Coyecque, 
Inventaire de la Collection Anisson sur I histoire de rimprimerie et de la librairie, principale- 
ment a Paris, 2 vols. (Paris, 1900), x-li. Sec also Frederick Charles Green, Eighteenth- 
Century France (London, 1929), 205-8. 

20. Bonnefon, 209. 

21. Mmc de Vandeul, xlvi. Andre Billy, cd., Oeuvres, by Diderot (Paris: Nouvclle Revue 

franc.aise, 1951 [ Bibliothequc dc la Pleiadc, No. 25]), 15, dates this in June 1747, but 
cites no authorities. 

22. Naigeon, 142-3 nn. A manuscript copy of the Promenade was in Maleshcrbes library in 

1789 (Wade, Clandestine Organization, 166); perhaps this was the confiscated manuscript 
itself. Cf. Venturi, Jeunessc, 171-4. 

23. Naigeon to Vandeul, August 1786 (Massiet du Bicst, Lettres inedites . . . [supra, ch. 2, 

note 10], 4). 

24. A.-T., I, 248. 

25. Nouvelle Biographic generale (Hoefer), s.v. Tuisicux, Philippc-Florent de, and Tuisicux, 

Madeleine d Arsant de 1 ; see also J. dc Boisjoslin and G. Mosse, Quelques meneuses 
d hommes au XVIII e sieclc: Madame de Puysicux; Sophie Volland; Mesdames d Epinay ct 
d Houdetot, Nouvelle Revue, nouvelle serie, xxxrv (1905), 519-21. De Puisieux is men 
tioned in the Encyc., i, xlv, as having aided Diderot in the description of several of the arts. 

26. A.-T., i, 25 n, 

27. Madeleine d Arsant de Puisieux, Les Caracteres, Seconde Partic (London, 1751), ii; in 
print by 8 Feb. 1751 (Corr. litt., n, 29). 

28. Mme de Vandeul, xlii. A police report on Diderot, evidently written in 1749 because it 

gives his age as thirty-six, says, II cst marie ct a cu ccpcndant Mad e de Puysieux pour 
Maitresse pendant assez de terns (B.N., MSS, Nouv. acq. fr. 10781, fol. 146). 

29. Mme dc Vandeul, xli. 

30. RQH, 109; Diderot, Corr., i, 145. 

31. Morley, Diderot and the Encyclopaedists, i, 42. 

32. Mme de Puisieux, Conseih a une amie (n.p., 1749), vii x. 

33. B.N., MSS, Nouv. acq. fr. 10783, fol. 51. 

34. Corr. litt., I, 281. 

35. Mme de Puisieux, Les Caracteres, Seconde Partie, iii, vi. Nevertheless, D Argenson remarked 

that Les Caracteres was attributed in part to Diderot (D Argenson, vi, i82n.). A letter 
from [J.-N.] Moreau, 19 April 1750, presumably to the Lieutenant-General of Police, said 
that the work was attributed to Diderot, although appearing under a lady s name (Bi- 
bliotheque de 1 Arsenal: Archives de la Bastille, 10302). Le Petit Reservoir (Berlin [The 
Hague]), i (1750), 316-23, printed some Extraits du Livrc intitule; les Caractercs de 
Madame Puisieux, attribue a Mr. Diderot qui s en deffcnd. 

36". Joseph de La Porte, Histoire litter air e des dames jran$oiscs t 5 vols. (Paris, 1769), v, 154. 
See also Sabatier de Castrcs, Les Trots Siecles, HI, 385-6; and Corr. ##* n 2 9> m 3 1 . 
viii, 17. 

37. Marie-Jeanne Phlipon, Mme Roland, Uemoires, ed. Cl. Perroud, 2 vols. (Paris, 1905)* > 144- 

38. Arthur M. Wilson, Unc Partie ineditc dc la lettrc de Diderot a Voltaire, le n juin I749/ 
RHLF, LI (1951), 259- 

39. Mme de Vandeul, xlii. Canon Marcel believed that Mme Diderot s mother died about 1745 

(Marcel, Le Mariage de Diderot, 9 n.). 

40. Rousseau, cd. Hachette, viii, 246-7. 

41. A.-T., i, 304-5; Georges Le Roy, La Psychologic de Condillac (Paris, I937> 92-3- 

42. Le Roy, 102; cf. E. Vacherot, in Dictionnaire des sciences philosophiques, ed. Ad. Franck, 

3d printing (Paris, 1885), s.v. Diderot, 388. 


43. Dictionnaire de biographic franc.aise, ed. J. Balteau, M. Barroux, and M. Prevost (Paris, 

44. ulTure i/FrOct. i 74 7, 92-109; in A.-T., rx, 156-67. The standard work on this 
subject (M.-D.-J. Engramclle, La Tonotechnie, ou I art de noter les cyhndres [Pans, 1775]) 
bears no evidence, however, of any influence of Diderot s ideas. 

45. Encyc., xv, 96-7; ibid. Planches, v, s.v. Xuthcrie, planchc rv. 

46. Gentleman s Magazine, xix (i749)> 339 

47. Cf. A.-T., ix, 77 n. 

48. Gentleman s Magazine, xix, 405. 

49. Percy A. Scholes, The Oxford Companion to Music, 8th ed. (London, 1950), 553- Dr. 
Scholes does not, however, mention Diderot s project. 

50 B-L de Muralt, Lettres sur les Anglois et les Francois (Bibliotheque dc la Revue de 
Littexature Compare, LXXXVI [Paris, 1933]), 168^171. These remarks were written not 
long before 1700, but not published until 1725 (ibid. 45), 

51. Herbert Dieckmann, cd., Le Philosophe. Texts and Interpretation (Washington University 
Studies, New Series, Language and Literature, No. 18 [St. Louis, 1948]), 2-3 et passim. 
Voltaire declared that this work was de 1 annee 1730* (Wade, Clandestine Organization, 


52. Dieckmann, Le Philosophe, 32, 42, 40, 58. 

53. Ibid. 68. 


1. Andre Cresson, Diderot: sa vie, son oeuvre (Paris, 1949)* 35- 

2. For a good description of previous compendiums and works of reference, see Cm, 225-38. 
3! Supplement to the Fourth, Fifth, and Sixth Editions of the Encyclopaedia Britannica, 6 vols. 

(Edinburgh, 1824), I, ii-iii. This work contains (i-ix) a good account of early encyclo 
pedias, including the one edited by Diderot. 

4. Ibid. iv. 

5. A.-T., xin, 132. 

6. Diderot was commenting upon Duhamel de Monceau s Traite de la culture des terres 
suivant les principes de M. Tull (1750-61). Regarding this work, see T. H. Marshall, 
Jethro Tull and the "New Husbandry" of the Eighteenth Century,* Economic History 
Review, n (1929-30), 51-2. 

7. A.-T., xrv, 456. 

8. Venturi, Origini, 1112. 

9. Lanson, Questions diverses . . . , RHLF, xix, 314. Regarding Ramsay, see Albert Cherel, 

Un Aventurier religieux au XVIII 6 siecle: Andre-Michel Ramsay (Paris, 1926), 182; and 
esp. concerning his Masonic activities, the note by Depping in Biographic universelle 
(Michaud)> s.v. Ramsay, Andre-Michel de, as also Gustave Bord, La Franc-Mafonnerie 
en France des origines a 1815 (Paris, 1908), 62-8. 

10. Diderot et I Encyclopedie: Exposition commemorative, cd. Georges Huard (Paris: Biblio 

theque nationale, 1951), 18. 

11. Lanson, Questions diverses . . . , RHLF, xix, 315-16; Albert Lantoine, Histoire de la 
Franc-Mofonnerie franfaise: La Fran c-Ma$onneric chez elle (Paris, 1925), 55 J Albert 
Lantoine, Le Rite ecossais ancien et accepts (Paris, 1930), 73; J. Emile Daruty, Recherches 
sur le rite ecossais ancien accepte (Paris, 1879), 85, 84-6 nn.; Bord, La Franc-Magonnerie, 
121-3, 327-8. Lc Gras, 31, argued that the Le Breton involved was not Andre-Francois; 
but Louis-Philippe May, Note sur les origines mac.onniques de I Encyclopedie, Revue de 
Synthese, xvii (1939), 182-4, was inclined to think that it was Andre-Franc. ois Lc Breton 
after all; and recent researches seem to have established the fact (Jean Gigot, Promenade 
cncyclopedique,* Cahiers Haut-Marnais, No. 24 [i er trimestre 1951], 70 n.; and Jean 
Pommier, reviewing M. Gigot s article, RHLF, LI [1951], 378). Nevertheless, the question 
is not yet fully settled: sec G.-H. Luquet, ^Encyclopedic fut-ellc une entreprise maconnique? 
RHLF, LIV (1954), 29-31. 

12. Bord, La Franc-Mafonnerie, xvii; also Le Gras, 21-2, 29-30; but cf. Pommier, RHLF, LI 

(1950, 378. 


13. Venturi, Origini, 130. Cf. Pierre Grosclaude, Un Audacieux Message: L Encyclopedie (Paris, 

1951), 198-9; and Luquet, loc. cit., RHLF, LIV (1954), 23-31. 

14. Memoire pour Andre-Francois Le Breton, . . . Contre Ic Sieur Jean Mills, se disant Gentil- 

homme Anglais (Paris: Le Breton, 1745), 2. 

15. 17 Feb. and 5 March 1745 (ibid. 2-3). 

1 6. 25 Feb. 1745 (B.N., MSS, Fr. 21997, fol. 103: Registre des privileges et permissions 
simples de la librairie ). Action of 26 March 1745: Arrest du Conseil d Etat du Roy, rendu 
au sujet du privilege ci-devant accorde pour I impression de I ouvrage intitule, Dictionnaire 
universel des Arts & des Sciences. Du 28 Aout 1745 (Paris: Imprimerie royale, 1745), 
i, mounted in B.N., MSS, Fr. 22176, foil. 202-3. Action of 13 April 1745: Privilege de 
I EncyclopMie de Chambers. Du 13 avril 1745,* printed in Luneau de Boisjermain, Piece 
justificative No. in. The privilege of 13 April 1745 is listed in a manuscript Registre des 
privileges accordes aux auteurs et libraires, 1742-1748 (B.N., MSS, Fr. 21958, fol. 374). 

17. The title page is reproduced by Douglas H. Gordon and Norman L. Torrey, The Censoring 

of Diderot s Encyclopedic and the Re-established Text (New York, 1947), facing p. 10. The 
prospectus is printed in Luneau de Boisjermain, Piece justificative No. VL 

1 8. Arrest . . . du 28 Aout 1745, 2. 

19. Journal de Trevoux, May 1745, 934-9; this quotation p. 937. See the equally warm 

remarks in Jugemens sur Quelques Outrages Nouveaux, vin (Avignon, 1745), 70-72. 

20. Memoire pour Andre -Francois Le Breton, 6ff. Even so, Le Breton signed a new contract 

with Mills on 7 July 1745, recognizing Mills s sole right in the enterprise; then, on 13 July, 
Mills retroceded to Le Breton one half of his rights (Arrest . . . du 28 Aout 1745, 1-2). 

21. Sommaire pour le Sieur Jean Mills, Gentilhomme Anglois, contre le Sieur le Breton, 
libraire-imprimeur a Paris (Paris: Prault, 1745), reprinted in Luneau de Boisjermain, 
Piece justificative No. rv. 

22. Memoire pour Andre-Francois Le Breton, 13. 

23. Memoire pour les libraires associes a VEncy elope die, contre le Sieur Luneau de Boisjermain 

(Paris: Le Breton, 1771), 3-4. 

24. DNB, s.v. Mills, John (d. 1784?), which also says that Sellius died in 1787 in an insane 

asylum at Charenton, near Paris. Mills was a co-translator of the Memoir es de Gatidence 
de Lucques (Paris, 1746), a Utopian novel by Simon Bcrington, The Memoirs of Signor 
Gaudentio di Lucca (London, 1737). It was said of Mills in Freron s publication, Lettres 
sur quelques ecrits de ce temps, vm (1753), 315, that il sgavoit mediocrement notrc 
langue. In the Avertissement to the second French edition (Amsterdam, 1753), Dupuy- 
Demportes, the French translator, refers to Miltz and says that he himself had to 
purger sa [Mills s] traduction des vices et des anglicismes qui lui echapperoient.* 

25. Arrest . . . du 28 Aout 1745, 3. A manuscript volume of Rapports et Decisions, Librairie/ 

constituting vol. 80 of the Anisson-Duperron collection, gives the minutes of discussions 
having to do with the revocation of the old license and the granting of a new one 
(B.N., MSS, Fr. 22140, foil. 102, 104, 105, 109,. 112). 

26. Jugemens sur Quelques Outrages Nouveaux, x, 106. This quotation was part of a lengthy 

article (ibid, x, 105-15) regarding the prospectus of the James Dictionnaire universel de 

27. May, 15-16. The contract was signed 18 Oct. 1745. Lc Breton kept a half -interest; each 

of the others had one-sixth. One of the signed copies of this contract is in B.N., MSS, 
Nouv. acq. fr. 3347, foil. 196-8. 

28. 14 Nov. 1745 (May, 17). 

29. Renewal of the privilege, 26 [or 28?] Dec. 1745: B.N., MSS, Fr. 21997,^0!. 103. Docu 

ment of 21 Jan. 1746, printed in Luneau de Boisjermain, Piece justificative No. vii. The 
renewal was entered in the books of the corporation of book publishers on 8 Feb. 1746 
(B.N., MSS, Fr. 21958, foil. 471-2). 

30. Memoire pour Andre-Francois Le Breton, 10. 

31. B.N., MSS, Fr. 21958, fol. 262. 

32. Diderot, Pensees philosophiqucs, ed. Niklaus, 48 n. 

33- May, 32-3. In the second half of 1746 Diderot received a total of 1,323 livres (May, 



34. Antoine-Nicolas dc Condorcct, Eloge dc M. 1 Abb* dc Gua, Oeuvres de Condorctt, 12 
vols. (Paris, 1847-9), in, 248. 

35. Venturi, Orfcww, 133. For another description, written about 1750, see Corr. Utt., i, 375. 

36. May, 1 8. 

37. May, 21, 19- e 

38. Condorcet, Eloge de M. 1 Abbe dc Gua, Ocuvres, in, 247-8. 

40" According to the Histoire de l f Academic Royale des Sciences ct Bellcs-Lettres, published 
(with separate pagination) in the Nouveaux Memoirs de I Academic Royale des Sciences 
ct Belles-Lettres, Annee MDCCLXX (Berlin, 1772), 52, the Abbe de Gua forma le 
premier cette grande entreprise. This Histoire was probably written by Formey, the 
permanent secretary of the Academy. Subsequent authorities agreeing with this view are 
Biographic universelle (Michaud), s.v. Gua de Halves ; Larousse, Grand Dictionnaire 
universe! du XIX 6 sieclc, s.v. Gua de Malves ; Maurice Tourneux in La Grande Encyclo 
pedic, xv, 1009, s.v. Encyclopedic ; May, 9 n. Douglas and Torrey, 11-12, believe that 
Diderot should be given the credit. 

41. Condorcet, Eloge de M. 1 Abbe de Gua, Oeuvres, in, 248. 

42. Naigeon, 45. 

43. May, 21. 

44. Ibid. Sometime before April 1748, Le Breton paid out 46 livres for a dinner given by 
the publishers for Diderot and D Alembert (ibid. 41). 

45. George R. Havens, The Age of Ideas: From Reaction to Revolution in Eighteenth-Century 
France (New York, 1955)* 33- 

46. Charles-Augustin Sainte-Beuve, Daguesseau, Causeries du lundi, ni, 426-7. 

47. B.N., MSS, Fr. 21958, foil 828-9. The decision to grant a new license was taken on 

14 March 1748 (B.N., MSS, Fr. 21997, foL 103). 

48. For the texts of the 1746 and 1748 licenses, see Luneau de Boisjermain, Pieces justificative! 

Nos. vn and vm. 

49. Chretien-Guillaume Lamoignon de Malesherbes, Memoire sur la liberte de la presse (Paris, 

1814), 89. Malesherbes is believed to have written this Memoire in 1790 (J.-P. Belin, Le 
Mouvement philosophise de 1748 a 1789 [Paris, 1913], 7). The principal biographer of 
D Aguesseau, Aime-Auguste Boullee, Histoire de la vie et des outrages du chancelier 
d Agucsseau, 2 vols. (Paris, 1835), n, 120-21, vaguely mentions the Chancellor s interest 
in Diderot, without substantiation. 

50. B.N., MSS, Fr. 22191, fol. 22. This autograph note is reproduced in AUP, xxn ([Oct.] 

1952), numero special, facing p. 72. 

51. Maurice Tourneux, Un Factum inconnu de Diderot (Paris, 1901), 40; cf. D Alembert s 

foreword to Vol. in of the Encyclopedic (Encyc., in, i). 


1. May, 44-5- 

2. Early recruits, though there is no evidence that it was Diderot who recruited them, were 

the Abbes Mallet and Yvon, who contributed articles on theology and ecclesiastical history 
(Venturi, Origini, 40, 136; cf. May, 40, 55). Sec D Alembert s obituary of Mallet (Encyc., 
vi, iii-v). 

3. Mme de Vandeul, xlii. 

4. As reported by the informer Bonin, 14 Feb. 1748 (Bibliothequc de l f Arsenal: Archives de 

la Bastille 10301); also Durand s signed statement (Bonnefon, 210). 

5. The Abbe de Voisenon, hostile to Diderot, remarks inaccurately that the Bijoux was 
Diderot s first work, and then says: . . . c est un vol qu il fit au Comte de Caylus, qui 
lui montra un manuscrit tire de la Bibliotheque du Roi . . . (Claude Henri de Fusee de 
Voisenon, Oeuvres complettes, 4 vols. [Paris, 1781], rv, 175). Cf. Guillaume Apollinaire, 
Fernand Fleuret, and Louis Perceau, UEnfer de la Bibliotheque nationale, 2nd ed. (Paris, 
1913)* 2 3; and S. Paul Jones, A List of French Prose Fiction from 1700 to 1750 (New 
York, 1939), 94, s.v. Bernis.* 


6. Cf. e.g. Pierre Trahard, Lcs Uaitres de la sensibilite francaise au XVIII siecle (1715-1789), 

4 vols. (Paris, I93 I ~3) IJ > 161-3; Marie-Louise Dufrenoy, L Orient romanesque en France, 
1704-1789, i vols. (Montreal, 1946-7), i, 112-17. 

7. Sermons: Mme de Vandeul, xxxiii; nature of the soul: see comment by Vartanian, Diderot 

and Descartes, 242-3. 

8. A.-T., iv, 279-80 nn. See Belaval, L Esthetique sans paradoxe de Diderot, 36, 39-40; and 

Havelock Ellis, Diderot/ The New Spirit, 4th ed. (Boston, 1926), 52. 

9. Karl Rosenkranz, Diderot s Leben und Werf^e, 2 vols. (Leipzig, 1866), I, 67, speaks of it 

as ein Meisterstiick ; see also Paul Hazard, European Thought in the Eighteenth Century: 
From Montesquieu to Lessing (New Haven, 1954), 28-9. 

10. Andre Gide, Journals, tr. and annotated by Justin O Brien, 4 vols. (New York, 1947-51), 

n 349- 

11. Henri Lefebvre, Diderot (Paris, 1949), 207. 

12. A.-T., rv, 135. 

13. B.N., MSS, Nouv. acq. fr. 1214, fol. in. 

14. For the German translations, see Abrahams, Diderot, franzosisch und deutsch, Romanische 

Forschungen, LI, 612, 387. 

15. George Saintsbury, A History of the French Novel, 2 vols. (London, 1917-19), I, 403. 

Saintsbury, in his French Literature and its Masters (New York, 1946), 249, refers to 
the Bijoux as Diderot s one hardly pardonable sin. Cf. John Garber Palachc, Four 
Novelists of the Old Regime (New York, 1926), 110-12. For good critical remarks by 
recent authors, sec Pommier, Diderot avant Vincennes, 59-72, and Venturi, Jeunesse, 123- 


1 6. Mesnard, Lc Caractere de Diderot, Revue- de la Mediterranee, vii, 278. 

17. Rene Jasinski, Histoire de la litterature francaise, 2 vols. (Paris, 1947), n, 208. 

1 8. Corr. litt., I, 139-40. 

19. L. Charpentier, Lettres critiques, sur divers cents de nos jours contraires a la Religion & 
aux moeurs, 2 vols. (London, 1751), n, 22. See also Pierre Clement, Les Cinq Annees 
Litter aires, ou Nouvelles litteraires, etc., des annees 1748, 1749, 1750, *75i, ct 1752, 4 vols. 
(The Hague, 1754), 1, 26-30. 

20. Naigeon, 37. 

21. Venturi, Jeunesse, 134, 370. 

22. A.-T., rv, 135. Cf. Roland Mortier, Lc Journal de Lecture de F.-M. Lcuchsenring (i775~ 

1779) et I esprit "philosophique", RLC, xxix (1955), 216. 

23. Bibliotheque de 1 Arsenal, Archives de la Bastille 10301. 

24. Pommier, Diderot avaiit Vincennes, 57-9, 7 2 ~7- 

25. Bonnefon, 209, 216. 

26. Printed in A.-T., rv, 381-441. See Venturi, Jeunesse, 138, and Dufrenoy, L Orient 
romanesque en France, 118-19. 

27. Bonnefon, 212. The license to publish was granted on 10 May 1748 (B.N., MSS, Fr. 21958, 
fol. 837). 

28. Bonnefon, 212. 

29. Benin s report, 29 Jan. 1748 (Bibliotheque de 1 Arsenal: Archives de la Bastille 

10301). Regarding the Lediard translation, Corr. litt., 11, 106-7; attribution to De Puisieux 
is in Catalogue generale des livres imprimes de la Bibliotheque nationale, xcn (1928), col. 

30. Bonnefon, 212. 

31. Corr, litt., i, 202, 313. 

32. B.N., MSS, Fr. 22157, fol. 31; published by David, Le Breton, and Durand. 

33. See the cryptic allusion in the Avertissement des editeurs (Encyc., vi, i). 

34. A.-T., DC, 75. 

35. A.-T., ix, 79-80, also 81 and n., and Diderot, Corr., i, 55-6, 56-7 nn.; but Venturi, 

Jeunesse, 341, is inclined to think that it was Mme de Puisieux who was meant. Diderot 
refers in Jacques le fataliste (A.-T., vi, 70-71) to the love affair of M. and Mme Premontval. 
It is probable that Diderot was well acquainted with them, and that he was present at 
some of the mathematical lectures given by Premontval from ca. 1737 to 1745- Cf, Andre- 
Pierre Lc Guay de Premontval, Memoir es (The Hague, 1749)1 cs 


36. A.-T., ix, 77. The Uemoires were mentioned favorably but superficially by Cle"ment, Cinq 

Annies Litteraires, i, 199-200 (20 April 1749)- 

37. Journal des S?avans, Annee i749> 8. 

38. /or7za/ dc Trevoux, April 1749, 620. 

39. Mercure de France, Sept. 1748, 135- 

J L^ Sbert &ocker [formerly Krakeur] and Raymond L. Krueger, The Marfiemarical 
Writings of Diderot, lot. noon (1941), **i cf. Gino Loria, Curve pun tpeaA, * vols. 

(Milan, 1930), n, 125 n. 
42 Julian Lowell Coolidge, TA* Mathematics of Great Amateurs (Oxford, 1949), i85- . 

43. Dieudonne Thi^bault, Afo Sow*** dc vingt ans de sejour a Berlin, 3 d ed., 4 vols. (Pans, 

44. AuSms S De 5 Morgan, A Budget cf Paradoxes (London, 1872), 250-51. De Morgan first 

published his version in a letter to the Athenaeum, 31 Dec. 1867 (ibid. 474;- 

45. E. T. Bell, Men of Mathematics (New York, I93?)> *47- 

46* Lancelot Hogben, Mathematics for the Million (New York, 1937), i3-*4- 
47 Bancroft H. Brown, The Euler-Diderot Anecdote, American Mathematical Monthly, XLIX 
fiQ42) 302-3; see also Dirk J. Struik, A Story concerning Euler and Diderot, Ists, xxxi 
(1939), 431-a; and R. J. Gillings, The So-called Euler-Diderot Incident/ American 
Mathematical Monthly, LXI (1954)* 77~ 8 - 

i Premiere Lettre d un dtoyen zele t qui n est ni chirurgien ni medecin, A M. D. M. . . . 
Ou I on propose un moyen